Amal Ashour

Prof. Dr. Amal Ashour

Taif University, Ta'if, Saudi Arabia
orcid

Research Focus & Metrics

Academic Career Length

54Years (1973-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 May 2019 in Scientific Reports
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ZIZehra Irshad
Zehra Irshad
MXMingzhan Xue
Mingzhan Xue
AAAmal Ashour
Amal Ashour
JLJames R. Larkin
James R. Larkin
Paul ThornalleyPaul Thornalley
Paul Thornalley
Naila RabbaniNaila Rabbani
Naila Rabbani
Metabolic dysfunction of endothelial cells in hyperglycemia contributes to the development of vascular complications of diabetes where increased reactive glycating agent, methylglyoxal (MG), is involved. We assessed if increased MG glycation induced proteotoxic stress, identifying related metabolic drivers and protein targets. Human aortal endothelial cells (HAECs) were incubated in high glucose concentration (20 mM versus 5 mM control) in vitro for 3–6 days. Flux of glucose metabolism, MG formation and glycation and changes in cytosolic protein abundances, MG modification and proteotoxic responses were assessed. Similar studies were performed with human microvascular endothelial HMEC-1 cells where similar outcomes were observed. HAECs exposed to high glucose concentration showed increased cellular concentration of MG (2.27 ± 0.21 versus 1.28 ± 0.03 pmol/106 cells, P < 0.01) and formation of MG-modified proteins (24.0 ± 3.7 versus 14.1 ± 3.2 pmol/106 cells/day; P < 0.001). In proteomics analysis, high glucose concentration increased proteins of the heat shock response – indicating activation of the unfolded protein response (UPR) with downstream inflammatory and pro-thrombotic responses. Proteins susceptible to MG modification were enriched in protein folding, protein synthesis, serine/threonine kinase signalling, glycolysis and gluconeogenesis. MG was increased in high glucose by increased flux of MG formation linked to increased glucose metabolism mediated by proteolytic stabilisation and increase of hexokinase-2 (HK-2); later potentiated by proteolytic down regulation of glyoxalase 1 (Glo1) - the major enzyme of MG metabolism. Silencing of Glo1, selectively increasing MG, activated the UPR similarly. Silencing of HK-2 prevented increased glucose metabolism and MG formation. trans-Resveratrol and hesperetin combination (tRES-HESP) corrected increased MG and glucose metabolism by increasing expression of Glo1 and decreasing expression of HK-2. Increased MG glycation activates the UPR in endothelial cells and thereby may contribute to endothelial cell dysfunction in diabetic vascular disease where tRES-HESP may provide effective therapy.

20 July 2016 in Glycoconjugate Journal
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Naila RabbaniNaila Rabbani
Naila Rabbani
AAAmal Ashour
Amal Ashour
Paul ThornalleyPaul Thornalley
Paul Thornalley
Protein glycation in biological systems occurs predominantly on lysine, arginine and N-terminal residues of proteins. Major quantitative glycation adducts are found at mean extents of modification of 1–5 mol percent of proteins. These are glucose-derived fructosamine on lysine and N-terminal residues of proteins, methylglyoxal-derived hydroimidazolone on arginine residues and Nε-carboxymethyl-lysine residues mainly formed by the oxidative degradation of fructosamine. Total glycation adducts of different types are quantified by stable isotopic dilution analysis liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring mode. Metabolism of glycated proteins is followed by LC-MS/MS of glycation free adducts as minor components of the amino acid metabolome. Glycated proteins and sites of modification within them – amino acid residues modified by the glycating agent moiety - are identified and quantified by label-free and stable isotope labelling with amino acids in cell culture (SILAC) high resolution mass spectrometry. Sites of glycation by glucose and methylglyoxal in selected proteins are listed. Key issues in applying proteomics techniques to analysis of glycated proteins are: (i) avoiding compromise of analysis by formation, loss and relocation of glycation adducts in pre-analytic processing; (ii) specificity of immunoaffinity enrichment procedures, (iii) maximizing protein sequence coverage in mass spectrometric analysis for detection of glycation sites, and (iv) development of bioinformatics tools for prediction of protein glycation sites. Protein glycation studies have important applications in biology, ageing and translational medicine – particularly on studies of obesity, diabetes, cardiovascular disease, renal failure, neurological disorders and cancer. Mass spectrometric analysis of glycated proteins has yet to find widespread use clinically. Future use in health screening, disease diagnosis and therapeutic monitoring, and drug and functional food development is expected. A protocol for high resolution mass spectrometry proteomics of glycated proteins is given.

3 March 2021 in Nanotechnology
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EEEnas Tawfik Enan
Enas Tawfik Enan
AAAmal Ashour
Amal Ashour
SBSakeenabi Basha
Sakeenabi Basha
NFNayef H Felemban
Nayef H Felemban
SESanaa M. F. Gad EL-Rab
Sanaa M. F. Gad EL-Rab
Background. The development of dental caries is associated with various microorganisms and secondary caries formation is the main cause of restorations failure. The advice for restorative dental materials that have antimicrobial properties has stimulated the introduction of materials containing different antibacterial agents. Objectives. The present study has been designed to synthesize silver nanoparticles (AgNPs) and incorporate AgNPs and amoxicillin into glass ionomer cement (GIC) to synergize its effect on oral microbes. The effect of the added antimicrobial agents on compressive strength (CS) of GIC was also evaluated. Material and methods. Biosynthesis of AgNPs was done using Cupressus macrocarpa extract and AgNPs were characterized. A total of 120 disc-shaped specimens were prepared and classified into 4 main groups where Group A includes conventional GIC, Groups B and C include GIC with AgNPs or amoxicillin, respectively, while Group D included GIC with both AgNPs and amoxicillin. Each group was tested for the antimicrobial activity against both Streptococcus mutans (S. mutans) and Staphylococcus aureus (S. aureus). The distribution of biofilm was examined via a scanning electron microscope. The CS of the tested material was measured using a Material Test System. Results. The UV−visible spectrum showed a peak of 429 nm. Transmission electron microscopy, x-ray diffraction pattern and Fourier transform infrared analysis confirmed the formation of AgNPs with spherical to oblong polydispersed particles of diameter in the range of 13.5–25.8 nm. The maximum inhibitory zone was recorded for group D against both tested bacteria with a mean of 29 mm at first 24 h period to 15 mm at three weeks and showed antimicrobial rate 92.2% and 92.56%, against both strains, respectively. Additionally, group D disintegrated the structure of S. aureus biofilm and even kill bacteria in the biofilms. The addition of AgNPs and amoxicillin caused an insignificant effect on CS of GIC. Conclusion. TheAgNPs showed a synergistic effect in combination with amoxicillin and GIC dental restorative material against studied microorganisms. The agents can be safely added with minimal effect on the mechanical properties of the original cement.

19 July 2018 in The Neuroradiology Journal
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NKNirmeen A Kishk
Nirmeen A Kishk
AEAsmaa M Ebraheim
Asmaa M Ebraheim
AAAmal Ashour
Amal Ashour
NBNashwa M Badr
Nashwa M Badr
MEMohamed A Eshra
Mohamed A Eshra
Purpose: Monitoring of raised intracranial pressure (ICP) in patients with idiopathic intracranial hypertension (IIH) is required to prevent secondary optic nerve damage. Sonographic measurement of the optic nerve sheath diameter (ONSD) is a noninvasive method to evaluate intracranial hypertension. Different ONSD cut-off values have been reported probably due to ethnic variations. Our aim was to determine optic nerve sonographic examination cut-off points to predict raised ICP in IIH patients. Methods: This case-control study was conducted on 99 IIH post-pubertal female patients (both probable and definite) and 35 age- and sex-matched healthy volunteers. Sonographic ONSD and optic nerve diameter (OND) were obtained 3 mm behind the posterior edge of the globe in a horizontal plane via a 7–13 MHz linear probe. Lumbar puncture was then carried out on the patients. Results: The opening cerebrospinal fluid pressure documented in the patient group was 279.64 ± 65.97 mm H2O. A statistically significant difference was found between IIH patients and controls regarding ONSD. The best ONSD cut-off value indicating raised ICP was 6.05 mm with an area under the curve of 0.850 (95% confidence interval 0.805 to 0.894, 73.2% sensitivity and 91.4% specificity). Regarding OND/ONSD ratio, there was an insignificant difference between both groups. Conclusion: Sonographic ONSD but not OND/ONSD ratio could offer a bedside adjunct or alternative indicator of elevated ICP in IIH patients. Ethnic differences, however, should be noted when using this parameter.

2 July 2021 in IEEE Access
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RMRomany Mansour
Romany Mansour
MAMaha M. Althobaiti
Maha M. Althobaiti
AAAmal Ashour
Amal Ashour
In recent times, internet of things (IoT) and wireless communication techniques become widely used in healthcare sector. Biomedical image processing is commonly employed to detect the existence of diseases using biomedical images. Tongue diagnosis is an efficient, non-invasive model to perform auxiliary diagnosis any time anywhere that is support the global necessity in the primary healthcare system. Conventionally, medical practitioners investigate the tongue features based on their expert’s knowledge comes from experience. In order to eradicate the qualitative aspects, tongue images can be quantitatively examined, offering an effective disease diagnostic process in such a way that the physical harm of the patients can be minimized. Numerous tongue image analysis approaches exist in the literature, it is required to develop automated deep learning (DL) models to diagnose the diseases using tongue image analysis. In this view, this paper designs an automated IoT and synergic deep learning based tongue color image (ASDL-TCI) analysis model for disease diagnosis and classification. The proposed ASDL-TCI model operates on major stages namely data acquisition, pre-processing, feature extraction, classification, and parameter optimization. Primarily, the IoT devices are used to capture the human tongue images and transmitted to the cloud for further analysis. In addition, median filtering based image pre-processing and SDL based feature extraction techniques are employed. Moreover, deep neural network (DNN) based classifier is applied to determine the existence of the diseases. Lastly, enhanced black widow optimization (EBWO) based parameter tuning process takes place to enhance the diagnostic performance. For assessing the effectual performance of the ASDL-TCI model, a set of simulations take place on benchmark tongue images and examined the results under distinct dimensions. The simulation outcome verified the enhanced diagnostic performance of the ASDL-TCI model over the compared methods with the maximum precision, recall, and accuracy of 0.984, 0.973, and 0.983.

18 June 2022 in Applied Sciences
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GNGeorge Ntourtoglou
George Ntourtoglou
FDFotini Drosou
Fotini Drosou
Theodoros ChatzimitakosTheodoros Chatzimitakos
Theodoros Chatzimitakos
Vassilis AthanasiadisVassilis Athanasiadis
Vassilis Athanasiadis
Eleni BozinouEleni Bozinou
Eleni Bozinou
Stavros I. LalasStavros I. Lalas
Stavros I. Lalas
Increasing the yield of extraction of bioactive compounds from plants is of high importance. Grape stems are widely discarded during the wine-making process, despite their high content in many valuable compounds. The aim of this work was to examine whether the use of pulsed electric field (PEF) treatment of the stems could increase the yield of polyphenol and volatile compounds in the extracts. For this reason, a relatively low-energy consuming PEF process was employed (low-electric field strength, 1 kV/cm) for a short time (30 min) at the grape stems. In addition, the effect of different solvents during this pretreatment step was examined. With the use of Folin–Ciocalteu assay, the extracts were compared with the respective control samples (not pretreated with PEF). Moreover, extracts were prepared to assess whether changes occur to the volatile profile of the extracts. The results were conclusive that not only PEF can increase the yield of polyphenols (up to 35% increase recorded), but also that the solvent used during PEF pretreatment can affect the process. Furthermore, a 234% increase in the total content of volatile compounds was recorded, when PEF was used as a pretreatment step. Therefore, the combination of PEF and ultrasound-assisted extraction is highly promising to obtain grape stem extracts with a higher content of bioactive compounds.