Browse publications by year: 2018

  1. Ranjani B, Kalaiyarasi J, Pavithra L, Devasena T, Pandian K, Gopinath SCB
    Mikrochim Acta, 2018 02 23;185(3):194.
    PMID: 29594516 DOI: 10.1007/s00604-018-2715-8
    A sensing device was constructed for the amperometric determination of nitrite. It is based on the use of titanium dioxide (TiO2) nanotubes template with natural fibers and carrying hemin acting as the electron mediator. A glassy carbon electrode (GCE) was modified with the hemin/TNT nanocomposite. The electrochemical response to nitrite was characterized by impedance spectroscopy and cyclic voltammetry. An amperometric study, performed at a working potential of + 0.75 V (vs. Ag/AgCl), showed the sensor to enable determination of nitrite with a linear response in the 0.6 to 130 μM concentration range and with a 59 nM limit of detection. Corresponding studies by differential study voltammetry (Ep = 0.75 V) exhibited a linear range from 0.6 × 10-6 to 7.3 × 10-5 M with a limit of detection of 84 nM. The sensing device was applied to the determination of nitrite in spiked tap and lake water samples. Graphical abstract Natural fibers templated synthesis of TNT immobilized hemin as electron transfer mediator for quantitative detection of nitrite with detection limit of 59 nM and good electrochemical sensitivity and the method can be used for quantitative determination of nitrite in water samples.
  2. Abdollahi Y, Sabbaghi S, Abouzari-Lotf E, Jahangirian H, Sairi NA
    Water Sci Technol, 2018 Mar;77(5-6):1493-1504.
    PMID: 29595152 DOI: 10.2166/wst.2018.017
    The global attention has been focused on degradation of the environmental organic pollutants through green methods such as advanced oxidation processes (AOPs) under sunlight. However, AOPs have not yet been efficient in function of the photocatalyst that has been used. In this work, firstly, CaCu3Ti4O12 nanocomposite was simultaneously synthesized and decorated in different amounts of graphene oxide to enhance photodegradation of the organics. The result of the photocatalyst characterization showed that the sample with 8% graphene presented optimum photo-electrical properties such as low band gap energy and a great surface area. Secondly, the photocatalyst was applied for photodegradation of an organic model in a batch photoreactor. Thirdly, to scale up the process and optimize the efficiency, the photodegradation was modeled by multivariate semi-empirical methods. As the optimized condition showed, 45 mg/L of the methyl-orange has been removed at pH 5.8 by 0.96 g/L of the photocatalyst during 288 min of the light irradiation. Moreover, the photodegradation has been scaled up for industrial applications by determining the importance of the input effective variables according to the following organics order > photocatalyst > pH > irradiation time.
    MeSH terms: Azo Compounds/chemistry; Graphite/chemistry; Oxidation-Reduction; Oxides/chemistry; Photolysis*; Sunlight*; Waste Disposal, Fluid; Water; Water Pollutants, Chemical/chemistry*; Nanocomposites/chemistry*
  3. Alayan HM, Alsaadi MA, Das R, Abo-Hamad A, Ibrahim RK, AlOmar MK, et al.
    Water Sci Technol, 2018 Mar;77(5-6):1714-1723.
    PMID: 29595174 DOI: 10.2166/wst.2018.057
    In this study, carbon species were grown on the surface of Ni-impregnated powder activated carbon to form a novel hybrid carbon nanomaterial by chemical vapor deposition. The carbon nanomaterial was obtained by the precipitation of the methane elemental carbon atoms on the surface of the Ni catalyst. The physiochemical properties of the hybrid material were characterized to illustrate the successful growth of carbon species on the carbon substrate. The response surface methodology was used for the evaluation of adsorption parameters effect such as pH, adsorbent dose and contact time on the percentage removal of MB dye from aqueous solution. The optimum conditions were found to be pH = 11, adsorbent dose = 15 mg and contact time of 120 min. The material we prepared showed excellent removal efficiency of 96% for initial MB concentration of 50 mg/L. The adsorption of MB was described accurately by the pseudo-second-order model with R2 of 0.998 and qe of 163.93 (mg/g). The adsorption system showed the best agreement with Langmuir model with R2 of 0.989 and maximum adsorption capacity (Qm) of 250 mg/g.
    MeSH terms: Adsorption; Carbon/chemistry*; Charcoal/chemistry; Hydrogen-Ion Concentration; Kinetics; Methylene Blue/chemistry*; Water Pollutants, Chemical/chemistry*; Nanostructures/chemistry*
  4. Farzin A, Ibrahim R, Madon Z, Basri H
    Am J Phys Med Rehabil, 2018 09;97(9):628-635.
    PMID: 29595585 DOI: 10.1097/PHM.0000000000000931
    OBJECTIVE: The main objective of the present trial was to evaluate the efficiency of a preventative multicomponent prospective memory training among healthy older adults.

    DESIGN: This study was a two-arm within-participants trial with 4- and 12-wk follow-ups. Allocation ratio was 1:1, and pretraining and posttraining measurements were included. A total number of 25 healthy older adults were enrolled (mean = 63.32, SD = 4.44). Participants were randomly allocated into two conditions: (a) prospective memory training: participants underwent a multicomponent prospective memory training, and (b) control: participants were not contacted during the training phase. After the training phase was finished, participants crossed over to undergo the condition they did not experience before. The differences between pretraining and posttraining measures of prospective memory, activities of daily living, negative mood (depression), and anxiety were assessed. All changes in the measurements were analyzed using general linear method. This trial is registered at https://www.isrctn.com (#ISRCTN57600070).

    RESULTS: Multicomponent prospective memory training program was significantly effective on both subjective and objective prospective memory performances among healthy older adults. Moreover, the training had significant positive effects on activities of daily living (independence) among participants. In addition, negative mood and anxiety levels were reduced after the training was finished.

    CONCLUSIONS: This multicomponent prospective memory training improved prospective memory performance and activities of daily living and reduce negative mood (depression) and anxiety levels among healthy older adults.

    MeSH terms: Activities of Daily Living; Anxiety; Depression; Depressive Disorder; Follow-Up Studies; Humans; Learning; Memory, Episodic
  5. Lim D, Ngeow WC
    J Oral Maxillofac Surg, 2018 06;76(6):1141-1142.
    PMID: 29596795 DOI: 10.1016/j.joms.2018.03.001
    MeSH terms: Dexamethasone*; Humans; Methylprednisolone*; Molar, Third; Postoperative Period
  6. Javid MT, Rahim F, Taha M, Rehman HU, Nawaz M, Wadood A, et al.
    Bioorg Chem, 2018 08;78:201-209.
    PMID: 29597114 DOI: 10.1016/j.bioorg.2018.03.022
    α-Glucosidase is a catabolic enzyme that regulates the body's plasma glucose levels by providing energy sources to maintain healthy functioning. 2-Amino-thiadiazole (1-13) and 2-amino-thiadiazole based Schiff bases (14-22) were synthesized, characterized by 1H NMR and HREI-MS and screened for α-glucosidase inhibitory activity. All twenty-two (22) analogs exhibit varied degree of α-glucosidase inhibitory potential with IC50 values ranging between 2.30 ± 0.1 to 38.30 ± 0.7 μM, when compare with standard drug acarbose having IC50 value of 39.60 ± 0.70 μM. Among the series eight derivatives 1, 2, 6, 7, 14, 17, 19 and 20 showed outstanding α-glucosidase inhibitory potential with IC50 values of 3.30 ± 0.1, 5.80 ± 0.2, 2.30 ± 0.1, 2.70 ± 0.1, 2.30 ± 0.1, 5.50 ± 0.1, 4.70 ± 0.2, and 5.50 ± 0.2 μM respectively, which is many fold better than the standard drug acarbose. The remaining analogs showed good to excellent α-glucosidase inhibition. Structure activity relationship has been established for all compounds. The binding interactions of these compounds were confirmed through molecular docking.
    MeSH terms: alpha-Glucosidases/metabolism*; Dose-Response Relationship, Drug; Humans; Structure-Activity Relationship; Thiadiazoles/pharmacology*; Thiadiazoles/chemistry; Molecular Structure; Molecular Docking Simulation*; Glycoside Hydrolase Inhibitors/chemical synthesis; Glycoside Hydrolase Inhibitors/pharmacology*; Glycoside Hydrolase Inhibitors/chemistry
  7. Mohamad NV, Ima-Nirwana S, Chin KY
    Drug Des Devel Ther, 2018;12:555-564.
    PMID: 29588572 DOI: 10.2147/DDDT.S158410
    Background: Patients receiving androgen deprivation therapy experience secondary hypogonadism, associated bone loss, and increased fracture risk. It has been shown that tocotrienol from Bixa orellana (annatto) prevents skeletal microstructural changes in rats experiencing primary hypogonadism. However, its potential in preventing bone loss due to androgen deprivation therapy has not been tested. This study aimed to evaluate the skeletal protective effects of annatto tocotrienol using a buserelin-induced osteoporotic rat model.

    Methods: Forty-six male Sprague Dawley rats aged 3 months were randomized into six groups. The baseline control (n=6) was sacrificed at the onset of the study. The normal control (n=8) received corn oil (the vehicle of tocotrienol) orally daily and normal saline (the vehicle of buserelin) subcutaneously daily. The buserelin control (n=8) received corn oil orally daily and subcutaneous buserelin injection (75 µg/kg) daily. The calcium control (n=8) was supplemented with 1% calcium in drinking water and daily subcutaneous buserelin injection (75 µg/kg). The remaining rats were given daily oral annatto tocotrienol at 60 mg/kg (n=8) or 100 mg/kg (n=8) plus daily subcutaneous buserelin injection (75 µg/kg) (n=8). At the end of the experiment, the rats were euthanized and their blood, tibia, and femur were harvested. Structural changes of the tibial trabecular and cortical bone were examined using X-ray micro-computed tomography. Femoral bone calcium content and biomechanical strength were also evaluated.

    Results: Annatto tocotrienol at 60 and 100 mg/kg significantly prevented the deterioration of trabecular bone and cortical thickness in buserelin-treated rats (P<0.05). Both doses of annatto tocotrienol also improved femoral biomechanical strength and bone calcium content in buserelin-treated rats (P<0.05). The effects of annatto tocotrienol were comparable to calcium supplementation.

    Conclusion: Annatto tocotrienol supplementation is effective in preventing degeneration of the bone induced by buserelin. Therefore, it is a potential antiosteoporotic agent for men receiving androgen deprivation therapy.

    MeSH terms: Animals; Bone and Bones/drug effects*; Bone and Bones/pathology*; Bone and Bones/chemistry; Buserelin*; Calcium/analysis*; Calcium/metabolism; Carotenoids/chemistry; Disease Models, Animal*; Dose-Response Relationship, Drug; Male; Osteoporosis/chemically induced*; Osteoporosis/drug therapy; Osteoporosis/prevention & control*; Plant Extracts/chemistry; Structure-Activity Relationship; Molecular Structure; Rats, Sprague-Dawley; Tocotrienols/isolation & purification; Tocotrienols/pharmacology*; Tocotrienols/chemistry; Bixaceae/chemistry*; Rats
  8. Najjar MF, Sulaiman SAS, Al Jeraisy M, Balubaid H
    Ther Clin Risk Manag, 2018;14:557-564.
    PMID: 29588595 DOI: 10.2147/TCRM.S157469
    Background: There is a difference between evidence-based guidelines for geriatric patients and clinical practice of physicians. Prescribing potentially inappropriate medications (PIMs) can be attributed to the fact that many physicians are not aware of PIMs usage.

    Aim: The aim of this study was to assess the effectiveness of a combined intervention program comprising an educational and clinical pharmacist intervention to reduce the incidence of PIMs among hospitalized geriatric patients.

    Methods: This was a prospective pre-test versus post-test design study. The screening tool of older persons' prescriptions, 2nd version, and 2015 American Geriatric Society Beers' criteria were used to assess the appropriateness of medications prescribed for geriatric inpatients. The study was carried out in the medical wards of the Department of Medicine at King Abdulaziz Medical City in Riyadh, Saudi Arabia.

    Results: Four hundred geriatric patients were enrolled in the study: 200 in a pre-intervention group (control) and 200 in the intervention group. After the combined intervention, the incidence rate of PIMs decreased significantly from 61% to 29.5% (p<0.001). Out of 317 recommendations given by the clinical pharmacist, the physicians accepted a total of 196 (61.83%) recommendations. The most common PIMs to avoid regardless of diagnosis of geriatric patients before interventions were first-generation antihistamines (46%), sliding scale insulin (18.5%), antipsychotics (6.5%), benzodiazepines (9.5%), and antiarrhythmic drugs (15%).

    Conclusion: Using a combined intervention program that comprises an educational intervention of updated evidence-based guidelines and clinical pharmacist intervention would add a significant value to improve prescribing patterns in hospitalized geriatric patients.

  9. Rautenberg TA, Zerwes U, Lee WS
    Clinicoecon Outcomes Res, 2018;10:169-178.
    PMID: 29588606 DOI: 10.2147/CEOR.S157606
    Objective: To perform cost utility (CU) and budget impact (BI) analyses augmented by scenario analyses of critical model structure components to evaluate racecadotril as adjuvant to oral rehydration solution (ORS) for children under 5 years with acute diarrhea in Malaysia.

    Methods: A CU model was adapted to evaluate racecadotril plus ORS vs ORS alone for acute diarrhea in children younger than 5 years from a Malaysian public payer's perspective. A bespoke BI analysis was undertaken in addition to detailed scenario analyses with respect to critical model structure components.

    Results: According to the CU model, the intervention is less costly and more effective than comparator for the base case with a dominant incremental cost-effectiveness ratio of -RM 1,272,833/quality-adjusted life year (USD -312,726/quality-adjusted life year) in favor of the intervention. According to the BI analysis (assuming an increase of 5% market share per year for racecadotril+ORS for 5 years), the total cumulative incremental percentage reduction in health care expenditure for diarrhea in children is 0.136578%, resulting in a total potential cumulative cost savings of -RM 73,193,603 (USD -17,983,595) over a 5-year period. Results hold true across a range of plausible scenarios focused on critical model components.

    Conclusion: Adjuvant racecadotril vs ORS alone is potentially cost-effective from a Malaysian public payer perspective subject to the assumptions and limitations of the model. BI analysis shows that this translates into potential cost savings for the Malaysian public health care system. Results hold true at evidence-based base case values and over a range of alternate scenarios.

  10. Sazali S, Rusdi A, Siti HT
    Surg J (N Y), 2018 Jan;4(1):e43-e45.
    PMID: 29588914 DOI: 10.1055/s-0038-1637008
    An anterior cruciate ligament (ACL) injury may be diagnosed by clinical examination and radiological investigation using magnetic resonance imaging or by arthroscopy.1,2Based on our experience, the ACL tear in concomitant chronic ACL and posterior cruciate ligament (PCL) deficient knees may produce knee laxity, which is more difficult to assess on clinical examination, which in turn may affect the management algorithm of the patient. Our hypothesis is that, in a concomitant chronic ACL and PCL injury, posterior capsular contracture and abnormal reattachment of torn ACL will result in less clinical and subjective laxity, preoperatively. The aim of this study is to review a cohort of patients who had undergone PCL reconstructive surgery and compare the preoperative clinical assessments with and without anesthesia with arthroscopic finding of ACL. This is to assess the accuracy and reliability of clinical ACL laxity tests in detecting ACL tear in chronic ACL and PCL injury.
  11. Bouman R, van Welzen P, Sumail S, Echevarria G, Erskine PD, van der Ent A
    Bot Stud, 2018 Mar 27;59(1):9.
    PMID: 29589161 DOI: 10.1186/s40529-018-0225-y
    BACKGROUND: Nickel hyperaccumulator plants are of much interest for their evolution and unique ecophysiology, and also for potential applications in agromining-a novel technology that uses plants to extract valuable metals from soil. The majority of nickel hyperaccumulators are known from ultramafic soils in tropical regions (Cuba, New Caledonia and Southeast Asia), and one genus, Phyllanthus (Phyllanthaceae), is globally the most represented taxonomic entity. A number of tropical Phyllanthus-species have the potential to be used as 'metal crops' in agromining operations mainly because of their ease in cultivation and their ability to attain high nickel concentrations and biomass yields.

    RESULTS: One of the most promising species globally for agromining, is the here newly described species Phyllanthus rufuschaneyi. This species can be classified in subgenus Gomphidium on account of its staminate nectar disc and pistillate entire style and represents the most western species of this diverse group. The flower structure indicates that this species is probably pollinated by Epicephala moths.

    CONCLUSIONS: Phyllanthus rufuschaneyi is an extremely rare taxon in the wild, restricted to Lompoyou Hill near Kinabalu Park in Sabah, Malaysia. Its utilization in agromining will be a mechanism for conservation of the taxon, and highlights the importance of habitat and germplasm preservation if rare species are to be used in novel green technologies.

  12. Balogun WG, Seeni A
    Science, 2018 03 09;359(6380):1111.
    PMID: 29590034 DOI: 10.1126/science.aar8549
  13. Yeoh PL, Hornetz K, Shauki NIA, Dahlui M
    Int J Qual Health Care, 2018 Jul 01;30(6):466-471.
    PMID: 29590356 DOI: 10.1093/intqhc/mzy041
    Objective: To assess the adequacy of antenatal care (ANC) and its association with pregnancy outcomes using an approach that includes adequacy of both utilization and content.

    Design: Retrospective cohort study.

    Setting and Participants: Women attending ANC at public-funded primary health clinics where data were extracted from individual records.

    Methods: Adequacy of utilization assessment was based on the concept of Adequacy of Prenatal Care Utilization index; adequacy of content assessed the recommended routine care received by the women according to local guidelines. Association between adequacy and pregnancy outcomes was examined using binary logistic regression.

    Main Outcome Measures: Pregnancy outcomes included preterm birth and low birth weight.

    Results: Sixty-three percent of women showed higher than recommended ANC utilization; 52% had <80% of recommended routine care content. Although not statistically significant, the odds of preterm birth was lower among women with adequate level of utilization compared with inadequate (adjusted odds ratios (aOR) = 2.34, 95% confidence interval (CI) 0.45-12.16) and intensive levels (aOR = 3.27, 95% CI 0.73-14.60). Regarding adequacy of content, women who received inadequate level of care content were associated with higher prevalence of preterm birth (aOR = 3.69, 95% CI 1.60-8.55).

    Conclusion: The study shows inadequate content is associated with higher prevalence of preterm birth and suggests that inadequate utilization increases the risk of preterm birth. It demonstrates the relevance of using both utilization and content assessment in evaluating quality of ANC. Further studies are encouraged to review the methods used.
    MeSH terms: Adolescent; Adult; Ambulatory Care Facilities; Delivery of Health Care*; Female; Humans; Infant, Low Birth Weight; Infant, Newborn; Malaysia/epidemiology; Pregnancy; Pregnancy Outcome*; Prenatal Care/standards*; Prenatal Care/utilization; Retrospective Studies; Cohort Studies; Premature Birth/epidemiology
  14. Sioson MS, Martindale R, Abayadeera A, Abouchaleh N, Aditianingsih D, Bhurayanontachai R, et al.
    Clin Nutr ESPEN, 2018 04;24:156-164.
    PMID: 29576355 DOI: 10.1016/j.clnesp.2017.11.008
    BACKGROUND & AIMS: Guidance on managing the nutritional requirements of critically ill patients in the intensive care unit (ICU) has been issued by several international bodies. While these guidelines are consulted in ICUs across the Asia-Pacific and Middle East regions, there is little guidance available that is tailored to the unique healthcare environments and demographics across these regions. Furthermore, the lack of consistent data from randomized controlled clinical trials, reliance on expert consensus, and differing recommendations in international guidelines necessitate further expert guidance on regional best practice when providing nutrition therapy for critically ill patients in ICUs in Asia-Pacific and the Middle East.

    METHODS: The Asia-Pacific and Middle East Working Group on Nutrition in the ICU has identified major areas of uncertainty in clinical practice for healthcare professionals providing nutrition therapy in Asia-Pacific and the Middle East and developed a series of consensus statements to guide nutrition therapy in the ICU in these regions.

    RESULTS: Accordingly, consensus statements have been provided on nutrition risk assessment and parenteral and enteral feeding strategies in the ICU, monitoring adequacy of, and tolerance to, nutrition in the ICU and institutional processes for nutrition therapy in the ICU. Furthermore, the Working Group has noted areas requiring additional research, including the most appropriate use of hypocaloric feeding in the ICU.

    CONCLUSIONS: The objective of the Working Group in formulating these statements is to guide healthcare professionals in practicing appropriate clinical nutrition in the ICU, with a focus on improving quality of care, which will translate into improved patient outcomes.

    MeSH terms: Asia/epidemiology; Critical Care*; Humans; Middle East/epidemiology; Nutritional Requirements; Pacific Islands/epidemiology; Nutrition Assessment*; Critical Illness/rehabilitation; Critical Illness/therapy*; Practice Guidelines as Topic; Nutritional Support/methods*; Nutritional Support/standards; Consensus*; Quality Improvement
  15. Hatai K, Kamada T, Lau LM, Kulip J, Phan CS, Vairappan CS
    Biocontrol Sci, 2018;23(1):35-39.
    PMID: 29576593 DOI: 10.4265/bio.23.35
     The antifungal activity of two Bornean medicinal wild gingers Plagiostachys megacarpa and Zingiber phillippsiae were examined against Lagenidium thermophilum. The most active extract was P. megacarpa at concentration of 320 µg/mL inhibiting both hyphal growth and zoospore production of L. thermophilum in 24 h. Toxicity tests were conducted using mud crab (Scylla tranquebarica) larva. Bath treatment of P. megacarpa at concentrations of 320 and 640 µg/mL for 24 h were highly effective against hyphae and zoospores of the strain and it is non-toxic to mud crab larva. Therefore, crude extracts P. megacarpa may be used as alternative treatment for marine Oomycete infection of mud crab.
    MeSH terms: Animals; Anti-Infective Agents/pharmacology*; Brachyura/microbiology*; Dose-Response Relationship, Drug; Infection/veterinary; Plant Extracts/pharmacology*; Asarum/chemistry*; Lagenidium/drug effects*
  16. Low YS, Islahudin F, Razali KAM, Adnan S
    Open AIDS J, 2018;12:11-19.
    PMID: 29576815 DOI: 10.2174/1874613601812010011
    BACKGROUND: Treatment options among Human Immunodeficiency Virus (HIV)-infected children are limited as only a few Highly Active Antiretroviral Therapy (HAART) are approved worldwide for paediatric use. Among children, frequent changes in HAART regimen can rapidly exhaust treatment options, and information addressing this issue is scarce.

    OBJECTIVE: The aim of the study was to determine factors associated with the modification of initial HAART regimen modification among HIV-infected children.

    METHOD: A retrospective study was performed among HIV-infected children aged 18 and below, that received HAART for at least six months in a tertiary hospital in Malaysia. Factors associated with modification of initial HAART regimen were investigated.

    RESULTS: Out of 99 patients, 71.1% (n=71) required initial HAART regime modification. The most common reason for HAART modification was treatment failure (n=39, 54.9%). Other reasons included drug toxicity (n=14, 19.7%), change to fixed-dose products (n=11, 15.5%), product discontinuation (n=4, 5.6%) and intolerable taste (n=3, 4.2%). The overall mean time retention on initial HAART before regimen modification was 3.32 year ± 2.24 years (95% CI, 2.79-3.85). Patient's adherence was the only factor associated with initial regimen modification in this study. Participants with poor adherence showed a five-fold risk of having their initial HAART regimen modified compared to those with good adherence (adjusted OR [95% CI], 5.250 [1.614 - 17.076], p = 0.006).

    CONCLUSION: Poor adherence was significantly associated with initial regimen modification, intervention to improve patient's adherence is necessary to prevent multiple regimen modification among HIV-infected children.

  17. Lu L, Jiang Y, Jaganathan R, Hao Y
    J Ophthalmol, 2018;2018:1694187.
    PMID: 29576875 DOI: 10.1155/2018/1694187
    Diabetic retinopathy (DR) is classically defined by its vascular lesions and damage in the neurons of the retina. The cellular and clinical elements of DR have many features of chronic inflammation. Understanding the individual cell-specific inflammatory changes in the retina may lead to novel therapeutic approaches to prevent vision loss. The systematic use of available pharmacotherapy has been reported as a useful adjunct tool to laser photocoagulation, a gold standard therapy for DR. Direct injections or intravitreal anti-inflammatory and antiangiogenesis agents are widely used pharmacotherapy to effectively treat DR and diabetic macular edema (DME). However, their effectiveness is short term, and the delivery system is often associated with adverse effects, such as cataract and increased intraocular pressure. Further, systemic agents (particularly hypoglycemic, hypolipidemic, and antihypertensive agents) and plants-based drugs have also provided promising treatment in the progression of DR. Recently, advancements in pluripotent stem cells technology enable restoration of retinal functionalities after transplantation of these cells into animals with retinal degeneration. This review paper summarizes the developments in the current and potential pharmacotherapy and therapeutic technology of DR. Literature search was done on online databases, PubMed, Google Scholar, clinitrials.gov, and browsing through individual ophthalmology journals and leading pharmaceutical company websites.
    MeSH terms: Diabetic Retinopathy*
  18. Garba L, Mohamad Yussoff MA, Abd Halim KB, Ishak SNH, Mohamad Ali MS, Oslan SN, et al.
    PeerJ, 2018;6:e4347.
    PMID: 29576935 DOI: 10.7717/peerj.4347
    Membrane-bound fatty acid desaturases perform oxygenated desaturation reactions to insert double bonds within fatty acyl chains in regioselective and stereoselective manners. The Δ9-fatty acid desaturase strictly creates the first double bond between C9 and 10 positions of most saturated substrates. As the three-dimensional structures of the bacterial membrane fatty acid desaturases are not available, relevant information about the enzymes are derived from their amino acid sequences, site-directed mutagenesis and domain swapping in similar membrane-bound desaturases. The cold-tolerantPseudomonassp. AMS8 was found to produce high amount of monounsaturated fatty acids at low temperature. Subsequently, an active Δ9-fatty acid desaturase was isolated and functionally expressed inEscherichia coli. In this paper we report homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerantPseudomonassp. AMS8 for the first time to the best of our knowledge. Three dimensional structure of the enzyme was built using MODELLER version 9.18 using a suitable template. The protein model contained the three conserved-histidine residues typical for all membrane-bound desaturase catalytic activity. The structure was subjected to energy minimization and checked for correctness using Ramachandran plots and ERRAT, which showed a good quality model of 91.6 and 65.0%, respectively. The protein model was used to preform MD simulation and docking of palmitic acid using CHARMM36 force field in GROMACS Version 5 and Autodock tool Version 4.2, respectively. The docking simulation with the lowest binding energy, -6.8 kcal/mol had a number of residues in close contact with the docked palmitic acid namely, Ile26, Tyr95, Val179, Gly180, Pro64, Glu203, His34, His206, His71, Arg182, Thr85, Lys98 and His177. Interestingly, among the binding residues are His34, His71 and His206 from the first, second, and third conserved histidine motif, respectively, which constitute the active site of the enzyme. The results obtained are in compliance with thein vivoactivity of the Δ9-fatty acid desaturase on the membrane phospholipids.
    MeSH terms: Amino Acid Sequence; Catalysis; Fatty Acids, Monounsaturated; Histidine; Phospholipids; Stearoyl-CoA Desaturase; Temperature; Mutagenesis, Site-Directed; Palmitic Acid; Catalytic Domain; Fatty Acid Desaturases; Molecular Dynamics Simulation
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