Displaying publications 3441 - 3460 of 7301 in total

Abstract:
Sort:
  1. Fulltext Synthesis of 4-(dimethylamino)pyridine propylthioacetate coated gold nanoparticles and their antibacterial and photophysical activity
    Anwar A, Khalid S, Perveen S, Ahmed S, Siddiqui R, Khan NA, et al.
    J Nanobiotechnology, 2018 Jan 29;16(1):6.
    PMID: 29378569 DOI: 10.1186/s12951-017-0332-z
    BACKGROUND: Gold nanoparticles are useful candidate for drug delivery applications and are associated with enhancement in the bioavailability of coated drugs and/or therapeutic agent. Since, heterocyclic compounds are known to exhibit antimicrobial potential against variety of pathogens, we designed this study to evaluate the antibacterial effects of gold nanoparticles conjugation with new synthesized cationic ligand; 4-Dimethyl aminopyridinium propylthioacetate (DMAP-PTA) in comparison with pure compound and antibiotic drug Pefloxacin. Antibacterial activity of DMAP-PTA coated gold nanoparticles was investigated against a fecal strain of E. coli (ATCC 8739).

    RESULTS: A new dimethyl aminopyridine based stabilizing agent named as DMAP-PTA was synthesized and used for stabilization of gold nanoparticles. Gold nanoparticles coated with DMAP-PTA abbreviated as DMAP-PTA-AuNPs were thoroughly characterized by UV-visible, FT-IR spectroscopic methods and transmission electron microscope before biological assay. DMAP-PTA, DMAP-PTA-AuNPs and Pefloxacin were examined for their antibacterial potential against E. coli, and the minimum inhibitory concentration (MIC) was determined to be 300, 200 and 50 µg/mL respectively. Gold nanoparticles conjugation was found to significantly enhance the antibacterial activity of DMAP-PTA as compared to pure compound. Moreover, effects of DMAP-PTA-AuNPs on the antibacterial potential of Pefloxacin was also evaluated by combination therapy of 1:1 mixture of DMAP-PTA-AuNPs and Pefloxacin against E. coli in a wide range of concentrations from 5 to 300 µg/mL. The MIC of Pefloxacin + DMAP-PTA-AuNPs mixture was found to be 25 µg/mL as compared to Pefloxacin alone (50 µg/mL), which clearly indicates that DMAP-PTA-AuNPs increased the potency of Pefloxacin. AFM analysis was also carried out to show morphological changes occur in bacteria before and after treatment of test samples. Furthermore, DMAP-PTA-AuNPs showed high selectivity towards Pefloxacin in spectrophotometric drug recognition studies which offers tremendous potential for analytical applications.

    CONCLUSIONS: Gold nanoparticles conjugation was shown to enhance the antibacterial efficacy of DMAP-PTA ligand, while DMAP-PTA-AuNPs also induced synergistic effects on the potency of Pefloxacin against E. coli. DMAP-PTA-AuNPs were also developed as Pefloxacin probes in recognizing the drug in blood and water samples in the presence of other drugs.

  2. Data for in-situ industrial site characterization with the applications of combined subsurface and surface mapping
    Arifin MH, Kayode JS, Azahar MA, Jamil H, Sabri SFA
    Data Brief, 2018 Jun;18:1864-1868.
    PMID: 29904689 DOI: 10.1016/j.dib.2018.04.119
    The paper presents the data from the surface and subsurface mapping of this area for the purpose of siting industrial city in the area. The field data collected combine with the borehole data was to successfully apply these to solving geological, environmental and engineering complications posed by the complexity of the subsurface geological structures underlain this area. The Electrical Resistivity, (ER) and Induced Polarization, (IP) data were initially processed using RES2DINV software model to generate the depth to the lithological units together with topographic correction. The 2-D ER and IP data were collected from 23rd April 2017 up until 7th May 2017 covering a total of about 17.6 km along 44 survey lines using ABEM Terrameter SAS4000 for the field measurement. A total of 20 Borehole logs data were recorded to better characterized in-situ, the subsurface geological formations emplaced in the study area. The study area is located at Bagan Datuk, Perak Darul Ridzuan situated on Latitude 2° 44.653'N and Longitudes 104° 28.79' E along the west coast Peninsula Malaysia. The topography of the area is generally flat low-laying and elevation range from about 0 m to 32 m above mean sea level (MSL).
  3. Fulltext Ischaemic haemorrhagic stroke in a child with new onset type 1 diabetes mellitus
    Mohd Nor NS, Fong CY, Rahmat K, Vanessa Lee WM, Zaini AA, Jalaludin MY
    Eur Endocrinol, 2018 Apr;14(1):59-61.
    PMID: 29922355 DOI: 10.17925/EE.2018.14.1.59
    Cerebral oedema is the most common neurological complication of diabetic ketoacidosis (DKA). However, ischaemic and haemorrhagic brain injury has been reported infrequently. A 10-year old girl who was previously well presented with severe DKA. She was tachycardic with poor peripheral perfusion but normotensive. However, two fast boluses totalling 40 ml/kg normal saline were given. She was transferred to another hospital where she was intubated due to drowsiness. Rehydration fluid (maintenance and 48-hour correction for 7.5% dehydration) was started followed by insulin infusion. She was extubated within 24 hours of admission. Her ketosis resolved soon after and subcutaneous insulin was started. However, about 48 hours after admission, her Glasgow Coma Scale score dropped to 11/15 (E4M5V2) with expressive aphasia and upper motor neuron signs. One dose of mannitol was given. Her symptoms improved gradually and at 26-month follow-up she had a near-complete recovery with only minimal left lower limb weakness. Serial magnetic resonance imaging brain scans showed vascular ischaemic injury at the frontal-parietal watershed regions with haemorrhagic transformation. This case reiterates the importance of monitoring the neurological status of patient's with DKA closely for possible neurological complications including an ischaemic and haemorrhagic stroke.
  4. Synthesis, in vitro and in silico studies of novel potent urease inhibitors: N-[4-({5-[(3-Un/substituted-anilino-3-oxopropyl)sulfanyl]-1,3,4-oxadiazol-2-yl}methyl)-1,3-thiazol-2-yl]benzamides
    Abbasi MA, Hassan M, Aziz-Ur-Rehman, Siddiqui SZ, Raza H, Shah SAA, et al.
    Bioorg Med Chem, 2018 07 30;26(13):3791-3804.
    PMID: 29903414 DOI: 10.1016/j.bmc.2018.06.005
    The present article describes the synthesis, in vitro urease inhibition and in silico molecular docking studies of a novel series of bi-heterocyclic bi-amides. The synthesis of title compounds was initiated by benzoylation, with benzoyl chloride (1), of the key starter ethyl 2-(2-amino-1,3-thiazol-4-yl)acetate (2) in weak basic aqueous medium followed by hydrazide formation, 4, and cyclization with CS2 to reach the parent bi-heterocyclic nucleophile, N-{4-[(5-sulfanyl-1,3,4-oxadiazol-2-yl)methyl]-1,3-thiazol-2-yl}benzamide (5). Various electrophiles, 8a-l, were synthesized by a two-step process and these were finally coupled with 5 to yield the targeted bi-heterocyclic bi-amide molecules, 9a-l. The structures of the newly synthesized products were corroborated by IR, 1H NMR, 13C NMR, EI-MS and elemental analysis. The in vitro screening of these molecules against urease explored that most of the compounds exhibit potent inhibitory potential against this enzyme. The compound 9j, with IC50 value of 2.58 ± 0.02 µM, exhibited most promising inhibitory activity among the series, relative to standard thiourea having IC50 value of 21.11 ± 0.12 µM. In silico studies fully augmented the experimental enzyme inhibition results. Chemo-informatics analysis showed that synthesized compounds (9a-l) mostly obeyed the Lipinski's rule. Molecular docking study suggested that ligand 9j exhibited good binding energy value (-7.10 kcal/mol) and binds within the active region of target protein. So, on the basis of present investigation, it was inferred that 9j may serve as a novel scaffold for designing more potent urease inhibitors.
  5. Cytotoxic, Antiproliferative and Apoptosis-inducing Activity of L-Amino Acid Oxidase from Malaysian Calloselasma rhodostoma on Human Colon Cancer Cells
    Zainal Abidin SA, Rajadurai P, Chowdhury MEH, Ahmad Rusmili MR, Othman I, Naidu R
    Basic Clin Pharmacol Toxicol, 2018 Nov;123(5):577-588.
    PMID: 29908095 DOI: 10.1111/bcpt.13060
    The aim of this study was to investigate the cytotoxic, antiproliferative activity and the induction of apoptosis by L-amino acid oxidase isolated from Calloselasma rhodostoma crude venom (CR-LAAO) on human colon cancer cells. CR-LAAO was purified using three chromatographic steps: molecular exclusion using G-50 gel filtration resin, ion-exchange by MonoQ column and desalted on a G25 column. The purity and identity of the isolated CR-LAAO was confirmed by SDS-PAGE and LC-MS/MS. CR-LAAO demonstrated time- and dose-dependent cytotoxic activity on SW480 (primary human colon cancer cells) and SW620 (metastatic human colon cancer cells) with an EC50 values of 6 μg/ml and 7 μg/ml at 48 hr, respectively. Quantification of apoptotic cells based on morphological features demonstrated significant increase in apoptotic cell population in both SW480 and SW620 cells which peaked at 48 hr. Significant increase in caspase-3 activity and reduction in Bcl-2 levels were demonstrated following CR-LAAO treatment. These data provide evidence on the potential anticancer activity of CR-LAAO from the venom of C. rhodostoma for therapeutic intervention of human colon cancer.
  6. Interferon-γ induces biphasic changes in caldesmon localization as well as adherens junction organization and expression in HUVECs
    Ng CT, Fong LY, Yong YK, Hakim MN, Ahmad Z
    Cytokine, 2018 11;111:541-550.
    PMID: 29909980 DOI: 10.1016/j.cyto.2018.06.010
    Endothelial barrier dysfunction leads to increased endothelial permeability and is an early step in the development of vascular inflammatory diseases such as atherosclerosis. Interferon-γ (IFN-γ), a proinflammatory cytokine, is known to cause increased endothelial permeability. However, the mechanisms by which IFN-γ disrupts the endothelial barrier have not been clarified. This study aimed to investigate how IFN-γ impairs the endothelial barrier integrity by specifically examining the roles of caldesmon, adherens junctions (AJs) and p38 mitogen-activated protein (MAP) kinase in IFN-γ-induced endothelial barrier dysfunction. IFN-γ exhibited a biphasic effect on caldesmon localization and both the structural organization and protein expression of AJs. In the early phase (4-8 h), IFN-γ induced the formation of peripheral caldesmon bands and discontinuous AJs, while AJ protein expression was unchanged. Interestingly, IFN-γ also stimulated caldesmon phosphorylation, resulting in actin dissociation from caldesmon at 8 h. Conversely, changes seen in the late phase (16-24 h) included cytoplasmic caldesmon dispersal, AJ linearization and junctional area reduction, which were associated with reduced membrane, cytoskeletal and total AJ protein expression. In addition, IFN-γ enhanced myosin binding to caldesmon at 12 h and persisted up to 24 h. Furthermore, inhibition of p38 MAP kinase by SB203580 did not reverse either the early or late phase changes observed. These data suggest that IFN-γ may activate signaling molecules other than p38 MAP kinase. In conclusion, our findings enhance the current understanding of how IFN-γ disrupts endothelial barrier function and reveal potential therapeutic targets, such as caldesmon and AJs, for the treatment of IFN-γ-associated vascular inflammatory diseases.
  7. Fulltext Risk factors of vitamin D deficiency among 15-year-old adolescents participating in the Malaysian Health and Adolescents Longitudinal Research Team Study (MyHeARTs)
    Quah SW, Abdul Majid H, Al-Sadat N, Yahya A, Su TT, Jalaludin MY
    PLoS One, 2018;13(7):e0200736.
    PMID: 30024934 DOI: 10.1371/journal.pone.0200736
    BACKGROUND: This study is to determine the prevalence and risk factors of vitamin D deficiency (vitamin D ≤ 50 nmol/L) among 15-year-old Malaysian adolescents. By identifying potential risk factors, prevention strategies and interventions can be carried out to improve the vitamin D status in adolescents.

    METHODS AND FINDINGS: Stratified random sampling design was used to select adolescents from 15 urban and rural secondary schools in Selangor, Perak and Kuala Lumpur, Malaysia. Data collection was carried out from 1st April 2014 to 30th June 2014. Information regarding socio-demographic characteristics, sun exposure and sun protective behaviours, clinical data and environmental factors were collected. Blood for total vitamin D was sampled. Descriptive and multivariate logistic regressions were performed. Total 1061 participants were analyzed (62% were female; mean age 15.1 ± 0.4 years). The prevalence of vitamin D deficiency was 33%. Mean vitamin D was lower in female (53 ± 15 nmol), obese (body fat percentage (≥25%m; ≥33.8%f) (56 ± 16 nmol/L), Malays (58 ± 18 nmol/L) and Indians (58 ± 15 nmol/L). In multivariate analysis, female (OR = 5.5; 95% CI: 3.4-7.5), Malay (OR = 3.2; 95% CI: 1.3-8.0), Indian (OR = 4.3; 95% CI: 1.6-12.0) and those always wearing long sleeve (OR = 2.4; 95% CI: 1.1-5.4) were more likely to have vitamin D deficiency. For female participants, ethnicity {Malays (OR = 6.7; 95% CI: 2.0-18.5), Indian (OR = 4.5; 95% CI: 1.8-19.3)} was an important risk factors. Cloud cover, school residence, skin pigmentation, sun-exposure and sun-protective behaviours were not significant risk factors. The limitation of this study was recall bias as it relied on self-reported on the sun exposure and protective behaviours. The diet factors were not included in this analysis.

    CONCLUSIONS: The prevalence of Vitamin D deficiency among Malaysian adolescents was considerable. Gender, ethnicity and clothing style were important risk factors.

  8. Fulltext Intersection and Complement Set (IACS) Method to Reduce Redundant Node in Mobile WSN Localization
    Mohd Zaid Harith MZ, Mohamed Noor N, Idna Idris MY, Mohd Tamil E
    Sensors (Basel), 2018 Jul 19;18(7).
    PMID: 30029508 DOI: 10.3390/s18072344
    The majority of the Wireless Sensor Network (WSN) localization methods utilize a large number of nodes to achieve high localization accuracy. However, there are many unnecessary data redundancies that contributes to high computation, communication, and energy cost between these nodes. Therefore, we propose the Intersection and Complement Set (IACS) method to reduce these redundant data by selecting the most significant neighbor nodes for the localization process. Through duplication cleaning and average filtering steps, the proposed IACS selects the normal nodes with unique intersection and complement sets in the first and second hop neighbors to localize the unknown node. If the intersection or complement sets of the normal nodes are duplicated, IACS only selects the node with the shortest distance to the blind node and nodes that have total elements larger than the average of the intersection or complement sets. The proposed IACS is tested in various simulation settings and compared with MSL* and LCC. The performance of all methods is investigated using the default settings and a different number of degree of irregularity, normal node density, maximum velocity of sensor node and number of samples. From the simulation, IACS successfully reduced 25% of computation cost, 25% of communication cost and 6% of energy consumption compared to MSL*, while 15% of computation cost, 13% of communication cost and 3% of energy consumption compared to LCC.
  9. N-(2-hydroxyphenyl)acetamide and its gold nanoparticle conjugation prevent glycerol-induced acute kidney injury by attenuating inflammation and oxidative injury in mice
    Siddiqui RA, Simjee SU, Kabir N, Ateeq M, Shah MR, Hussain SS
    Mol Cell Biochem, 2019 Jan;450(1-2):43-52.
    PMID: 29790115 DOI: 10.1007/s11010-018-3371-3
    The protective activity of N-(2-hydroxyphenyl)acetamide (NA-2) and NA-2-coated gold nanoparticles (NA-2-AuNPs) in glycerol-treated model of acute kidney injury (AKI) in mice was investigated. NA-2 (50 mg/kg) and NA-2-AuNPs (30 mg/kg) were given to the animals for four days followed by 24-h water deprivation and injection of 50% glycerol (10 ml/kg im). The animals were sacrificed on the next day. Blood and kidneys were collected for biochemical investigations (urea and creatinine), histological studies (hematoxylin and eosin; and periodic acid-Schiff staining), immunohistochemistry (actin and cyclooxygenase-2, Cox-2), and real-time RT-PCR (inducible nitric oxide synthase, iNOS; nuclear factor-κB p50, NFκB; hemeoxygenase-1, HO-1; and kidney injury molecule-1, Kim-1). NA-2 protected renal tubular necrosis and inflammation, though the result of NA-2-AuNPs was better than compound alone and it also exhibited the activity at far less dose. The test compound and its gold nano-formulation decreased the levels of serum urea and creatinine level in the treated animals. Both NA-2 and NA-2-AuNPs also conserved actin cytoskeleton, and lowered COX-2 protein expression. Moreover, the mRNA expressions of iNOS and NFkB p50 were down-regulated, and HO-1 and Kim-1 genes were up-regulated. We conclude that NA-2 and NA-2-AuNPs ameliorates kidney inflammation and injury in glycerol-induced AKI animal model via anti-oxidant and anti-inflammatory mechanisms which make it a suitable candidate for further studies. We believe that these findings will contribute in the understanding of the mechanism of action of paracetamol-like drugs and can be considered for clinical research for the prevention of AKI.
  10. Carbon nanotube scaffolds as emerging nanoplatform for myocardial tissue regeneration: A review of recent developments and therapeutic implications
    Gorain B, Choudhury H, Pandey M, Kesharwani P, Abeer MM, Tekade RK, et al.
    Biomed Pharmacother, 2018 Aug;104:496-508.
    PMID: 29800914 DOI: 10.1016/j.biopha.2018.05.066
    Myocardial infarction (cardiac tissue death) is among the most prevalent causes of death among the cardiac patients due to the inability of self-repair in cardiac tissues. Myocardial tissue engineering is regarded as one of the most realistic strategies for repairing damaged cardiac tissue. However, hindrance in transduction of electric signals across the cardiomyocytes due to insulating properties of polymeric materials worsens the clinical viability of myocardial tissue engineering. Aligned and conductive scaffolds based on Carbon nanotubes (CNT) have gained remarkable recognition due to their exceptional attributes which provide synthetic but viable microenvironment for regeneration of engineered cardiomyocytes. This review presents an overview and critical analysis of pharmaceutical implications and therapeutic feasibility of CNT based scaffolds in improving the cardiac tissue regeneration and functionality. The expository analysis of the available evidence revealed that inclusion of single- or multi-walled CNT into fibrous, polymeric, and elastomeric scaffolds results in significant improvement in electrical stimulation and signal transduction through cardiomyocytes. Moreover, incorporation of CNT in engineering scaffolds showed a greater potential of augmenting cardiomyocyte proliferation, differentiation, and maturation and has improved synchronous beating of cardiomyocytes. Despite promising ability of CNT in promoting functionality of cardiomyocytes, their presence in scaffolds resulted in substantial improvement in mechanical properties and structural integrity. Conclusively, this review provides new insight into the remarkable potential of CNT aligned scaffolds in improving the functionality of engineered cardiac tissue and signifies their feasibility in cardiac tissue regenerative medicines and stem cell therapy.
  11. The Modified Urdu version of International Prostate Symptom Score: A psychometric validation study
    Salman M, Khan AH, Sulaiman SAS, Hughes J, Khan JH, Hussain K
    Turk J Urol, 2018 Jul;44(4):335-340.
    PMID: 29932403 DOI: 10.5152/tud.2018.44834
    OBJECTIVE: The objective of the current study was to develop an Urdu version of the International Prostate Symptom Score (IPSS-U) and validate it for Pakistani patients suffering from lower urinary tract symptoms (LUTS).
    MATERIAL AND METHODS: IPSS-U was developed by a two-step forward and back translation and to evaluate its psychometric properties, a prospective study involving patients suffering from LUTS (n=267) was conducted at Outpatient Urology Department, Mayo Hospital, Lahore, Pakistan. Internal consistency and reproducibility were assessed using Cronbach's alpha and the Intra-Class Correlation Coefficient (ICC). Moreover, exploratory, and confirmatory factor analyses were performed to determine dimensionality of IPSS-U items.
    RESULTS: Overall reliability of IPSS-U was satisfactory (Cronbach's alpha=0.72, ICC of symptom questions=0.92 and ICC of QOL index=0.75). Exploratory factor analysis revealed that two factors were consistent, which together explained 59.8% of the variance. IPSS-U items 1, 3, 5 and 6 were components of the first factor whereas item 2, 4 and 7 were components of the second factor. All the items loaded high on their factors and there were no cross loadings. Moreover, confirmatory factor analysis also showed two-factor model, with acceptable fitting patterns.
    CONCLUSION: IPSS-U is a valid and reliable non-gender specific instrument to assess the frequency and severity of LUTS in Urdu-speaking population.
  12. Re-Expression of Bone Marrow Proteoglycan-2 by 5-Azacytidine is associated with STAT3 Inactivation and Sensitivity Response to Imatinib in Resistant CML Cells
    Al-Jamal HAN, Johan MF, Mat Jusoh SA, Ismail I, Wan Taib WR
    Asian Pac J Cancer Prev, 2018 Jun 25;19(6):1585-1590.
    PMID: 29936783
    Background: Epigenetic silencing of tumor suppressor genes (TSG) is involved in development and
    progression of cancers. Re-expression of TSG is inversely proportionate with STAT3 signaling pathways.
    Demethylation of DNA by 5-Azacytidine (5-Aza) results in re-expression of silenced TSG. Forced expression of
    PRG2 by 5-Aza induced apoptosis in cancer cells. Imatinib is a tyrosine kinase inhibitor that potently inhibits BCR/
    ABL tyrosine kinase resulting in hematological remission in CML patients. However, majority of CML patients treated
    with imatinib would develop resistance under prolonged therapy. Methods: CML cells resistant to imatinib were
    treated with 5-Aza and cytotoxicity of imatinib and apoptosis were determined by MTS and annexin-V, respectively.
    Gene expression analysis was detected by real time-PCR, STATs activity examined using Western blot and methylation
    status of PRG2 was determined by pyrosequencing analysis. Result: Expression of PRG2 was significantly higher in
    K562-R+5-Aza cells compared to K562 and K562-R (p=0.001). Methylation of PRG2 gene was significantly decreased
    in K562-R+5-Aza cells compared to other cells (p=0.021). STAT3 was inactivated in K562-R+5-Aza cells which showed
    higher sensitivity to imatinib. Conclusion: PRG2 gene is a TSG and its overexpression might induce sensitivity to
    imatinib. However, further studies are required to evaluate the negative regulations of PRG2 on STAT3 signaling.
  13. Fulltext Prevalence and associated factors of stress, anxiety and depression among emergency medical officers in Malaysian hospitals
    Yahaya SN, Wahab SFA, Yusoff MSB, Yasin MAM, Rahman MAA
    World J Emerg Med, 2018;9(3):178-186.
    PMID: 29796141 DOI: 10.5847/wjem.j.1920-8642.2018.03.003
    BACKGROUND: Demanding profession has been associated with poor psychological health due to multiple factors such as overworking hours and night shifts. This study is to determine prevalence and associated factors of depression, anxiety and stress among medical officers working at emergency department in Malaysian hospitals.

    METHODS: A cross-sectional study was conducted on 140 emergency department medical officers working at general hospitals from seven Malaysia regions. They were randomly selected and their depression, anxiety and stress level were measured by the 21-item Depression, Anxiety, Stress Scale.

    RESULTS: The highest prevalence was anxiety (28.6%) followed by depression (10.7%) and stress (7.9%). Depression, anxiety and stress between seven hospitals were not significantly different (P>0.05). Male medical officers significantly experienced more anxiety symptoms than female medical officers (P=0.0022), however depression and stress symptoms between male and female medical officers were not significantly different (P>0.05). Depression, anxiety and stress were not associated with age, working experience, ethnicity, marital status, number of shifts and type of system adopted in different hospitals (P>0.05).

    CONCLUSION: The prevalence of anxiety was high, whereas for depression and stress were considerably low. Gender was the only factor significantly associated with anxiety. Other factors were not associated with depression, anxiety and stress. Future research should aim to gain better understanding on unique factors that affect female and male medical officers' anxiety level in emergency setting, thus guide authorities to chart strategic plans to remedy this condition.

  14. Fulltext Synthesis, enzyme inhibitory kinetics mechanism and computational study of N-(4-methoxyphenethyl)-N-(substituted)-4-methylbenzenesulfonamides as novel therapeutic agents for Alzheimer's disease
    Abbasi MA, Hassan M, Aziz-Ur-Rehman, Siddiqui SZ, Shah SAA, Raza H, et al.
    PeerJ, 2018;6:e4962.
    PMID: 29967717 DOI: 10.7717/peerj.4962
    The present study comprises the synthesis of a new series of sulfonamides derived from 4-methoxyphenethylamine (1). The synthesis was initiated by the reaction of 1 with 4-methylbenzenesulfonyl chloride (2) in aqueous sodium carbonate solution at pH 9 to yield N-(4-methoxyphenethyl)-4-methylbenzensulfonamide (3).This parent molecule 3 was subsequently treated with various alkyl/aralkyl halides, (4a-j), using N,N-dimethylformamide (DMF) as solvent and LiH as activator to produce a series of new N-(4-methoxyphenethyl)-N-(substituted)-4-methylbenzenesulfonamides (5a-j). The structural characterization of these derivatives was carried out by spectroscopic techniques like IR, 1H-NMR, and 13C-NMR. The elemental analysis data was also coherent with spectral data of these molecules. The inhibitory effects on acetylcholinesterase and DPPH were evaluated and it was observed that N-(4-Methoxyphenethyl)-4-methyl-N-(2-propyl)benzensulfonamide (5c) showed acetylcholinesterase inhibitory activity 0.075 ± 0.001 (IC50 0.075 ± 0.001 µM) comparable to Neostigmine methylsulfate (IC50 2.038 ± 0.039 µM).The docking studies of synthesized ligands 5a-j were also carried out against acetylcholinesterase (PDBID 4PQE) to compare the binding affinities with IC50 values. The kinetic mechanism analyzed by Lineweaver-Burk plots demonstrated that compound (5c) inhibits the acetylcholinesterase competitively to form an enzyme inhibitor complex. The inhibition constants Ki calculated from Dixon plots for compound (5c) is 2.5 µM. It was also found from kinetic analysis that derivative 5c irreversible enzyme inhibitor complex. It is proposed on the basis of our investigation that title compound 5c may serve as lead structure for the design of more potent acetylcholinesterase inhibitors.
  15. Biomechanical features of six design of the delta external fixator for treating Pilon fracture: a finite element study
    Ramlee MH, Sulong MA, Garcia-Nieto E, Penaranda DA, Felip AR, Kadir MRA
    Med Biol Eng Comput, 2018 Oct;56(10):1925-1938.
    PMID: 29679256 DOI: 10.1007/s11517-018-1830-3
    Pilon fractures can be caused by high-energy vertical forces which may result in long-term patient immobilization. Many experts in orthopedic surgery recommend the use of a Delta external fixator for type III Pilon fracture treatment. This device can promote immediate healing of fractured bone, minimizing the rate of complications as well as allowing early mobilization. The characteristics of different types of the Delta frame have not been demonstrated yet. By using the finite element method, this study was conducted to determine the biomechanical characteristics of six different configurations (Model 1 until Model 6). CT images from the lower limb of a healthy human were used to reconstruct three-dimensional models of foot and ankle bones. All bones were assigned with isotropic material properties and the cartilages were assigned to exhibit hyperelasticity. A linear link was used to simulate 37 ligaments at the ankle joint. Axial loads of 70 and 350 N were applied at the proximal tibia to simulate the stance and swing phase. The metatarsals and calcaneus were fixed distally in order to prevent rigid body motion. A synthetic ankle bone was used to validate the finite element model. The simulated results showed that Delta3 produced the highest relative micromovement (0.09 mm, 7 μm) during the stance and swing phase, respectively. The highest equivalent von Mises stress was found at the calcaneus pin of the Delta4 (423.2 MPa) as compared to others. In conclusion, Delta1 external fixator was the most favorable option for type III Pilon fracture treatment. Graphical abstract ᅟ.
  16. Fulltext Optimization of a closed rat tibial fracture model
    Handool KO, Ibrahim SM, Kaka U, Omar MA, Abu J, Yusoff MSM, et al.
    J Exp Orthop, 2018 May 02;5(1):13.
    PMID: 29721763 DOI: 10.1186/s40634-018-0128-6
    BACKGROUND: The use of a closed fracture model has become the preferred model to study the fracture healing process, given that the periosteum and the soft tissue surrounding the fracture site play an important role in the fracture healing process. Some techniques like osteotomy, drilling the long bones and the use of the guillotine-like apparatus to induce fracture are characterized by some undesirable effects and complications. The aim of this study is to optimize and evaluate an in vivo fracture model using three-point bending pliers that can be used to study secondary bone fracture healing in rats.

    METHODS: Modified three-point bending pliers were used as a device to create the closed rat tibial bone fracture that was prefixed with an intramedullary pin (23 G × 11/2″) in rats. The exact location of the induced closed fracture was along the long bone. The presence of bone comminution, and the fracture bone alignment were immediately examined after the induction of the fracture until the 6th week.

    RESULTS: All fractures induced were transverse, located in the middle to proximal one third of the tibia, and they all healed without complications. Bone union as shown radiographically occurred within 2-3 weeks postoperative. The average angle of the fracture line with the axis of the tibia was 89.41 ± 2.11°. The lateral and anterio-posterior pin angulation views were 167.33 ± 3.67° and 161.60 ± 4.87° respectively. The average length of proximal end of the fractured bone in comparison with the whole length of intact bone was 41.02 ± 3.27%. There was a significant difference in percentage of the gross callus area and gross callus index, while there was no significant difference in X-ray callus index. There was no significant difference of the gross callus area between slight comminution (n = 4) and non comminution (n = 21).

    CONCLUSION: The optimized rat tibial fracture model resulted in mainly transverse tibial mid-shaft fractures with minimal bone comminution and absence of surrounding soft tissue damage. The size area of consequent soft callus formation and the extent to which the closed fracture model was reproducible are very good outcomes making it feasible for in vivo laboratory research use.

  17. Fulltext Metabolite Profiling of the Microalgal Diatom Chaetoceros Calcitrans and Correlation with Antioxidant and Nitric Oxide Inhibitory Activities via ¹H NMR-Based Metabolomics
    Azizan A, Ahamad Bustamam MS, Maulidiani M, Shaari K, Ismail IS, Nagao N, et al.
    Mar Drugs, 2018 May 07;16(5).
    PMID: 29735927 DOI: 10.3390/md16050154
    Microalgae are promising candidate resources from marine ecology for health-improving effects. Metabolite profiling of the microalgal diatom, Chaetoceros calcitrans was conducted by using robust metabolomics tools, namely ¹H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate data analysis (MVDA). The unsupervised data analysis, using principal component analysis (PCA), resolved the five types of extracts made by solvents ranging from polar to non-polar into five different clusters. Collectively, with various extraction solvents, 11 amino acids, cholesterol, 6 fatty acids, 2 sugars, 1 osmolyte, 6 carotenoids and 2 chlorophyll pigments were identified. The fatty acids and both carotenoid pigments as well as chlorophyll, were observed in the extracts made from medium polar (acetone, chloroform) and non-polar (hexane) solvents. It is suggested that the compounds were the characteristic markers that influenced the separation between the clusters. Based on partial least square (PLS) analysis, fucoxanthin, astaxanthin, violaxanthin, zeaxanthin, canthaxanthin, and lutein displayed strong correlation to 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and nitric oxide (NO) inhibitory activity. This metabolomics study showed that solvent extractions are one of the main bottlenecks for the maximum recovery of bioactive microalgal compounds and could be a better source of natural antioxidants due to a high value of metabolites.
  18. Fulltext A Review on Systems-Based Sensory Gloves for Sign Language Recognition State of the Art between 2007 and 2017
    Ahmed MA, Zaidan BB, Zaidan AA, Salih MM, Lakulu MMB
    Sensors (Basel), 2018 Jul 09;18(7).
    PMID: 29987266 DOI: 10.3390/s18072208
    Loss of the ability to speak or hear exerts psychological and social impacts on the affected persons due to the lack of proper communication. Multiple and systematic scholarly interventions that vary according to context have been implemented to overcome disability-related difficulties. Sign language recognition (SLR) systems based on sensory gloves are significant innovations that aim to procure data on the shape or movement of the human hand. Innovative technology for this matter is mainly restricted and dispersed. The available trends and gaps should be explored in this research approach to provide valuable insights into technological environments. Thus, a review is conducted to create a coherent taxonomy to describe the latest research divided into four main categories: development, framework, other hand gesture recognition, and reviews and surveys. Then, we conduct analyses of the glove systems for SLR device characteristics, develop a roadmap for technology evolution, discuss its limitations, and provide valuable insights into technological environments. This will help researchers to understand the current options and gaps in this area, thus contributing to this line of research.
  19. Fulltext Determinants of High Fasting Insulin and Insulin Resistance Among Overweight/Obese Adolescents
    Ling JC, Mohamed MN, Jalaludin MY, Rampal S, Zaharan NL, Mohamed Z
    Sci Rep, 2016 11 08;6:36270.
    PMID: 27824069 DOI: 10.1038/srep36270
    Hyperinsulinaemia is the earliest subclinical metabolic abnormality, which precedes insulin resistance in obese children. An investigation was conducted on the potential predictors of fasting insulin and insulin resistance among overweight/obese adolescents in a developing Asian country. A total of 173 overweight/obese (BMI > 85th percentile) multi-ethnic Malaysian adolescents aged 13 were recruited from 23 randomly selected schools in this cross-sectional study. Waist circumference (WC), body fat percentage (BF%), physical fitness score (PFS), fasting glucose and fasting insulin were measured. Insulin resistance was calculated using homeostasis model assessment of insulin resistance (HOMA-IR). Adjusted stepwise multiple regression analysis was performed to predict fasting insulin and HOMA-IR. Covariates included pubertal stage, socioeconomic status, nutritional and physical activity scores. One-third of our adolescents were insulin resistant, with girls having significantly higher fasting insulin and HOMA-IR than boys. Gender, pubertal stage, BMI, WC and BF% had significant, positive moderate correlations with fasting insulin and HOMA-IR while PFS was inversely correlated (p 
  20. Inhibition of UVB-induced pro-inflammatory cytokines and MMP expression by Zanthoxylum rhetsa bark extract and its active constituent hesperidin
    Santhanam RK, Fakurazi S, Ahmad S, Abas F, Ismail IS, Rukayadi Y, et al.
    Phytother Res, 2018 Aug;32(8):1608-1616.
    PMID: 29672974 DOI: 10.1002/ptr.6092
    The antiphoto aging property of Zanthoxylum rhetsa obtained from Pangkor Island, Malaysia, was evaluated. Solvent fractions of different polarity obtained from the methanolic extract of the bark material were initially tested for anticollagenase and antielastase activities. The ethyl acetate fraction showed bioactivity against the protease enzymes. Hence, it was subjected to further purification via column chromatography, to yield a major constituent, hesperidin. Subsequently, the ethyl acetate fraction and hesperidin were tested for their effects against UVB-induced cytotoxicity and expressions of inflammatory cytokines (IL-6, IL-1β, and TNF-α), NF-κB, and MMPs (MMP1, 3, and 9) in human dermal fibroblasts (HDF). Both fraction and pure compound prevented UVB-induced cytotoxicity in HDF cells, in a dose dependent manner. Moreover, the ethyl acetate fraction inhibited the increase of pro-inflammatory cytokines induced by UVB to a level similar to the control (without UV treatment). Additionally, the fraction significantly inhibited the expressions of NF-κB, MMP 1, MMP 3, and MMP 9 in HDF cells treated with UVB. Similar effects were observed with hesperidin. The results obtained suggested that the ethyl acetate fraction of Z. rhetsa and its bioactive constituent, hesperidin, have the potential to be used as active ingredients in sunscreen and antiphoto aging formulations.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links