Books by Mohamed M I Mohamed
Instinctive Plant tolerance towards abiotic stresses in arid regions
Trace Elements in the environment
Papers by Mohamed M I Mohamed
Macrocyclic peptidomimetics with antimicrobial activity: synthesis, bioassay, and molecular modeling studies
Organic & biomolecular chemistry, Jan 10, 2015
Novel, cyclic peptidomimetics were synthesized by facile acylation reactions using benzotriazole ... more Novel, cyclic peptidomimetics were synthesized by facile acylation reactions using benzotriazole chemistry. Microbiological testing of the synthesized compounds revealed an exceptionally high activity against Candida albicans with a minimum inhibitory concentration (MIC) two orders of magnitude lower than the MIC of the antifungal reference drug amphotericin B. A strikingly high activity was also observed against three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Proteus vulgaris), two of which are known human pathogens. Thus the discovered chemotype is a potential polypharmacological agent. The toxicity against mammalian tumor cells was found to be low, as demonstrated in five different human cell lines (HeLa, cervical; PC-3, prostate; MCF-7, breast; HepG2, liver; and HCT-116, colon). The internal consistency of the experimental data was studied using 3D-pharmacophore and 2D-QSAR.
Saudi Journal of Biological Sciences, 2015
Soil contamination with petroleum hydrocarbon products such as diesel and engine oil is becoming ... more Soil contamination with petroleum hydrocarbon products such as diesel and engine oil is becoming one of the major environmental problems. This study describes hydrocarbons degrading bacteria (PHAD) isolated from long-standing petrol polluted soil from the eastern region, Dammam, Saudi Arabia. The isolated strains were firstly categorized by accessible shape detection, physiological and biochemistry tests. Thereafter, a technique established on the sequence analysis of a 16S rDNA gene was used. Isolation of DNA from the bacterial strains was performed, on which the PCR reaction was carried out. strains were identified based on 16Sr DNA sequence analysis, As follows amplified samples were spontaneously sequenced automatically and the attained results were matched to open databases. Among the isolated bacterial strains, S1 was identified as Staphylococcus aureus and strain S1 as Corynebacterium amycolatum.
Transpinal Constant Current Long-Lasting Stimulation: A New Method to Induce Cortical and Corticospinal Plasticity
Journal of neurophysiology, Jan 24, 2015
Functional neuroplasticity in response to stimulation and motor training is a well-established ph... more Functional neuroplasticity in response to stimulation and motor training is a well-established phenomenon. Transcutaneous stimulation of the spine is used mostly to alleviate pain, but it may also induce functional neuroplasticity, because the spinal cord serves as an integration center for descending and ascending neuronal signals. In this work, we examined whether long-lasting noninvasive cathodal and anodal transpinal constant current stimulation (c-tsCCS, a-tsCCS) over the thoracolumbar enlargement can induce cortical, corticospinal, and spinal neuroplasticity. Twelve healthy human subjects, blind to the stimulation protocol, were randomly assigned to 40 min of c-tsCCS or a-tsCCS. Before and after transpinal stimulation, we established the afferent-mediated motor evoked potential (MEP) facilitation and the subthreshold TMS-mediated flexor reflex facilitation. Recruitment input-output curves of MEPs and transpinal evoked potentials (TEPs), and post-activation depression of the so...
Journal of Ophthalmic Inflammation and Infection, 2015
Background: The National Eye Institute 39-Question Visual Function Questionnaire (NEI VFQ-39) is ... more Background: The National Eye Institute 39-Question Visual Function Questionnaire (NEI VFQ-39) is an indicator of vision-related quality of life (QoL). The NEI VFQ-39 is used to assess the QoL in patients with non-infectious posterior uveitis, intermediate uveitis, or panuveitis, treated with subconjunctival (SCJ) or intravitreal (IVT) sirolimus as an immunomodulatory therapeutic (IMT) agent, delivered subconjunctivally (SCJ) or intravitreally (IVT) (the SAVE Study). Thirty subjects with non-infectious uveitis were randomized (SCJ:IVT, 1:1) for a prospective clinical trial. The 39-Question Visual Function Questionnaire (VFQ-39) was administered at baseline (BL), month 6 (M6), and month 12 (M12) visits. The survey measures self-reported vision health status for patients with chronic eye disease and assesses the effects of visual impairment on both task-oriented visual function and general health domains. In accordance to the NEI-VFQ Manual, each patient's questionnaire was converted to a scaled score between 0 (worst) and 100 (best), and median scores were calculated for each of the subcategories and overall composite score at BL, M6, and M12. Wilcoxon signed-rank test was performed. Results: Twenty-six patients completed the VFQ-39 at BL and M6, whereas 23 patients completed it at M12. Patients showed a significant improvement in pooled composite scores from BL to M6 and BL to M12. Analysis by treatment groups showed that intravitreal injection of sirolimus is better tolerated. Conclusions: Sirolimus has demonstrated bioactivity as an IMT and corticosteroid-sparing agent to treat non-infectious uveitis. Patients receiving intravitreal injection of sirolimus showed overall improvement of vision-related health while those receiving subconjunctival injections did not. Larger randomized control trials with sirolimus are indicated to validate these results.
One-Year Outcomes of the SAVE Study: S irolimus as a Therapeutic A pproach for U VE itis
Translational Vision Science & Technology, 2015
To determine the efficacy and safety of repeated intravitreal and subconjunctival administrations... more To determine the efficacy and safety of repeated intravitreal and subconjunctival administrations of sirolimus in patients with noninfectious uveitis at 1 year in the Sirolimus as a Therapeutic Approach UVEitis (SAVE) Study. Open-label, prospective, and randomized interventional clinical trial in which 30 patients with noninfectious intermediate, posterior, or panuveitis were randomized 1:1 to receive sirolimus 352-μg intravitreal or 1320-μg subconjunctival. Sirolimus was administered at days 0, 60, and 120. At month 6, all subjects were allowed to receive sirolimus at intervals greater than or equal to 2 months and until month 12. Changes in vitreous haze (VH), visual acuity (VA), and retinal thickness at month 12 were compared with baseline. Of patients with active uveitis at baseline (n = 20), 70% showed greater than or equal to 2 steps reduction of VH at month 12 (P < 0.05), 88% (n = 7) of patients with inactive uveitis at baseline showed either no change or reduction of VH to no haze, 36% (n = 10) of all patients (n = 28) gained greater than or equal to one line of VA, 21% (n = 6) lost greater than or equal to 1 line, and 43% (n = 12) showed no change. At the end of 1 year, no statistical differences in efficacy were found between intravitreal and subconjunctival groups. No serious adverse events were determined to be secondary to sirolimus. Repeated subconjunctival/intravitreal injections of sirolimus appear to be tolerated by patients with noninfectious uveitis over 12 months. Results from the index study suggest that sirolimus may provide benefits to patients with uveitis. Both intravitreal and subconjunctival routes demonstrate similar bioactivity/efficacy. The intravitreal route, however, was better tolerated. The SAVE Study illustrates for the first time the application of local formulations of sirolimus in non-infectious intermediate, posterior, and pan-uveitis. Subconjunctival/Intravitreal sirolimus may help to control inflammation while offering better tolerability/safety profiles than systemic therapies, including immunosuppressants and corticosteroids.
Orthogonal hydrogen/halogen bonding in 1-(2-methoxyphenyl)-1H-imidazole-2(3H)-thione-I2 adduct: An experimental and theoretical study
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, Jan 14, 2015
The molecular complex between 1-(2-methoxyphenyl)-1H-imidazole-2(3H)-thione (Hmim(OMe)) and iodin... more The molecular complex between 1-(2-methoxyphenyl)-1H-imidazole-2(3H)-thione (Hmim(OMe)) and iodine (I2) was investigated. Single crystal of [(Hmim(OMe))I2] adduct was grown by slow evaporation technique from chloroform at room temperature. Spectroscopic techniques such as FT-IR and Raman techniques, as well as elemental and thermal analysis were used to characterize the complex. The crystal structure shows that the formed adduct stabilized by two noncovalent interactions, namely, hydrogen bond (HB) and halogen bond (XB). Orthogonal HB/XB associated with iodine atom (I) was observed and fully characterized. The ability of iodine to behave as hydrogen bond acceptor and halogen bond donor was held responsible for the orthogonal HB/XB presence. In addition, the structure of Hmim(OMe)I2 was investigated theoretically using MP2/aug-cc-pVDZ level of theory. Natural bond orbital analysis (NBO) was used to investigate the molecular orbitals interactions and orbitals stabilization energies.
Quantitative imaging in medicine and surgery, 2015
To assess oxygen saturation (StO2) in retinal vessels of normal subjects and diabetic patients wi... more To assess oxygen saturation (StO2) in retinal vessels of normal subjects and diabetic patients with and without retinopathy using the modified version of the Flow Oximetry System (FOS) and a novel assessment software. The FOS and novel assessment software were used to determine StO2 levels in arteries and veins located between 1 and 2 mm from the margin of the optic disc and in the macular area. Eighteen normal subjects, 15 diabetics without diabetic retinopathy (DM no DR), and 11 with non-proliferative diabetic retinopathy (NPDR) were included in final analysis. The mean [± standard deviation (SD)] StO2 in retinal arteries was 96.9%±3.8% in normal subjects; 97.4%±3.7% in DM no DR; and 98.4%±2.0% in NPDR. The mean venous StO2 was 57.5%±6.8% in normal subjects; 57.4%±7.5% in DM no DR; and 51.8%±6.8% in NPDR. The mean arterial and venous StO2 across the three groups were not statistically different (P=0.498 and P=0.071, respectively). The arterio-venous differences between the three s...
Radiation synthesis and characterization of polyamidoamine dendrimer macromolecules with different loads of nickel salt for adsorption of some metal ion
Radiation Physics and Chemistry, 2007
Graft copolymer networks of poly(methacrylic acid-g-polyamidoamine dendrimer) with different load... more Graft copolymer networks of poly(methacrylic acid-g-polyamidoamine dendrimer) with different loads of nickel salt were synthesized by gamma radiation-induced copolymerization of polyamidoamine dendrimer and methacrylic acid (MAA). Nickel release and metal adsorption from the polymeric systems, and their thermal stability were analyzed. A high percentage of the nickel loaded was released, although strong interactions between the polymeric matrices and the nickel
Methicillin-resistant Staphylococcus aureus (MRSA)-active metabolites from Platanus occidentalis (American Sycamore)
Journal of natural products, 2009
One known and three new potent, selective, and nontoxic anti-MRSA metabolites, kaempferol…
BMC pharmacology & toxicology, Jan 14, 2013
This study was designed to assess the safety, tolerability, and efficacy of intravenous infusion ... more This study was designed to assess the safety, tolerability, and efficacy of intravenous infusion of CA4P in patients with neovascular age-related macular degeneration (AMD). Prospective, interventional, dose-escalation clinical trial. Eight patients with neovascular AMD refractory to at least 2 sessions of photodynamic therapy received CA4P at a dose of 27 or 36 mg/m2 as weekly intravenous infusion for 4 consecutive weeks. Safety was monitored by vital signs, ocular and physical examinations, electrocardiogram, routine laboratory tests, and collection of adverse events. Efficacy was assessed using retinal fluorescein angiography, optical coherence tomography, and best corrected visual acuity (BCVA). The most common adverse events were elevated blood pressure (46.7%), QTc prolongation (23.3%), elevated temperature (13.3%), and headache (10%), followed by nausea and eye injection (6.7%). There were no adverse events that were considered severe in intensity and none resulted in discont...
Assessment of Central Retinal Sensitivity Employing Two Types of Microperimetry Devices
Translational vision science & technology, 2014
To compare the retinal sensitivity measurements obtained with two microperimeters, the Micro-Peri... more To compare the retinal sensitivity measurements obtained with two microperimeters, the Micro-Perimeter 1 (MP-1) and the Optos optical coherence tomography (OCT)/scanning laser ophthalmoscope (SLO) in subjects with and without maculopathies. Forty-five eyes with no known ocular disease and 47 eyes with maculopathies were examined using both microperimeters. A contrast-adjusted scale was applied to resolve the different stimuli and background luminance existing between the two devices. There was a strong ceiling effect with the MP-1 in the healthy group, with 90.1% (1136 of 1260) test points clustered at 20 dB. The mean sensitivity for the corresponding points in the OCT/SLO was 25.8 ± 1.9 dB. A floor effect was also observed with the OCT/SLO in the maculopathy group with 9.7% (128 of 1316) points clustered at 9-dB values. The corresponding mean sensitivity in the MP-1 was 1.7 ± 3.9 dB. A regression equation between the two microperimeters was established in the common 10 to19 dB inte...
Crosswell Seismic Amplitude-Versus-Offset for Detailed Imaging of Facies and Fluid Distribution within Carbonate Oil Reservoirs
Crosswell seismic surveys were conducted at two fields in northern Michigan. One of these, Spring... more Crosswell seismic surveys were conducted at two fields in northern Michigan. One of these, Springdale, included two monitor wells that are located external to the reef, and the other, Coldspring, employed two production wells within the reef. The Springdale wells ...
Innovative Analytical Team Approach to Restore Integrity of Challenging Wells, Salvage Gas Tower and Used to Eliminate Complex and Costly Gas Well Workover
Abu Dhabi International Petroleum Exhibition and Conference, 2010
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This paper provides both the theoretical and practical results for Geo-stationary satellites orbi... more This paper provides both the theoretical and practical results for Geo-stationary satellites orbit determination using both dual Ranging from Two (2) separate earth station locations and Classical orbit determination from an earth station.
Tetrahedron Letters, 2008
a b s t r a c t A new ligand, namely, N-{tris([2-[(1-methylbenzimidazol-2-yl)ethyl]methyl]amino)-... more a b s t r a c t A new ligand, namely, N-{tris([2-[(1-methylbenzimidazol-2-yl)ethyl]methyl]amino)-2-oxoethyl}iminodiacetic acid is synthesized and characterized and used to prepare a zinc complex as a promising model for the active site of the nacreous protein in mollusc shells. Preliminary investigation of CO 2 fixation and calcification is studied with regard to the influence of the pK a value of the coordinated water molecule and the carboxylate groups. (M. M. Ibrahim).
Proceedings of the National Academy of Sciences, 2013
Development of an X-ray Computed Tomography System for Non-Invasive Imaging of Industrial Materials
X-ray computed tomography is a powerful non-invasive imaging technique for viewing an object'... more X-ray computed tomography is a powerful non-invasive imaging technique for viewing an object's inner structures in two-dimensional cross-section images without the need to physically section it. The invention of CT techniques revolutionised the field of medical diagnostic imaging because it provided more detailed and useful information than any previous non-invasive imaging techniques. The method is increasingly being used in industry, aerospace, geosciences and archaeology. This paper describes the development of an X-ray computed tomography system for imaging of industrial materials. The theoretical aspects of CT scanner, the system configurations and the adopted algorithm for image reconstruction are discussed. The penetrating rays from a 160 kV industrial X-ray machine were used to investigate structures that manifest in a manufactured component or product. Some results were presented in this paper.
Minor Diterpene Glycosides from the Leaves of Stevia rebaudiana
Journal of Natural Products, 2014
Two new diterpene glycosides in addition to five known glycosides have been isolated from a comme... more Two new diterpene glycosides in addition to five known glycosides have been isolated from a commercial extract of the leaves of Stevia rebaudiana. Compound 1 (rebaudioside KA) was shown to be 13-[(O-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid 2-O-β-d-glucopyranosyl-β-d-glucopyranosyl ester and compound 2, 12-α-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid β-d-glucopyranosyl ester. Five additional known compounds were identified, rebaudioside E, rebaudioside M, rebaudioside N, rebaudioside O, and stevioside, respectively. Enzymatic hydrolysis of stevioside afforded the known ent-kaurane aglycone 13-hydroxy-ent-kaur-16-en-19-oic acid (steviol) (3). The isolated metabolite 1 possesses the ent-kaurane aglycone steviol (3), while compound 2 represents the first example of the isomeric diterpene 12-α-hydroxy-ent-kaur-16-en-19-oic acid existing as a glycoside in S. rebaudiana. The structures of the isolated metabolites 1 and 2 were determined based on comprehensive 1D- and 2D-NMR (COSY, HSQC, and HMBC) studies. A high-quality crystal of compound 3 has formed, which allowed the acquisition of X-ray diffraction data that confirmed its structure. The structural similarities between the new metabolites and the commercially available stevioside sweeteners suggest the newly isolated metabolites should be examined for their organoleptic properties. Accordingly rebaudiosides E, M, N, O, and KA have been isolated in greater than gram quantities.
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Books by Mohamed M I Mohamed
Papers by Mohamed M I Mohamed