Publications by authors named "Ahmed Abdelal"

Background The treatment of varicose veins has undergone tremendous changes over the years. High ligation of the saphenofemoral junction (SFJ) and stripping of the great saphenous vein (GSV) have been considered standard treatments for GSV insufficiency for over a century and are still adopted as the preferred method in the majority of surgical centers in North Africa. However, the increase in minimally invasive treatments such as endovenous thermal ablation (EVTA), radiofrequency ablation (RFA), ultrasound-guided foam sclerotherapy, and cryo-stripping has produced excellent results.

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Introduction: Thompson and Austin Moore prostheses have been commonly used in hemiarthroplasties for displaced femoral neck fractures. There has been considerable debate about which of these prostheses is preferred. The purpose of this meta-analysis was to compare historical data for clinical outcomes of cemented Thompson and uncemented Austin Moore hemiarthroplasty in displaced femoral neck fractures.

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The carboxylesterase Est55 has been cloned and expressed in Bacillus subtilis strains. Est55, which lacks a classical, cleavable N-terminal signal sequence, was found to be secreted during the stationary phase of growth such that there is more Est55 in the medium than inside the cells. Several cytoplasmic proteins were also secreted in large amounts during late stationary phase, indicating that secretion in B.

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Est30 is a thermophilic carboxylesterase cloned from Geobacillus stearothermophilus that showed optimal hydrolysis of esters with short acyl chains at 70 degrees C. Est30 is a member of a new family of carboxylesterases with representatives in other Gram-positive bacteria. The crystal structure has been determined at 1.

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The arginine regulatory protein of Pseudomonas aeruginosa, ArgR, is essential for induction of operons that encode enzymes of the arginine succinyltransferase (AST) pathway, which is the primary route for arginine utilization by this organism under aerobic conditions. ArgR also induces the operon that encodes a catabolic NAD(+)-dependent glutamate dehydrogenase (GDH), which converts l-glutamate, the product of the AST pathway, in alpha-ketoglutarate. The studies reported here show that ArgR also participates in the regulation of other enzymes of glutamate metabolism.

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Screening of the genomic libraries of Geobacillus stearothermophilus ATCC12980 and ATCC7954 for esterase/lipase activity led to the isolation of two positive clones. The results of subclonings and sequence analyses identified two genes, est30 and est55, encoding two different carboxylesterases, and genetic rearrangement in the est55 locus was revealed from genomic comparison. The est30 gene encodes a polypeptide of 248 amino acids with a calculated molecular mass of 28338 Da, and the est55 gene encodes a polypeptide of 499 amino acids with a calculated molecular mass of 54867 Da.

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Five genes from the ilv-leu operon from Bacillus stearothermophilus have been sequenced. Acetohydroxyacid synthase (AHAS) and its subunits were separately cloned, purified, and characterized. This thermophilic enzyme resembles AHAS III of Escherichia coli, and regulatory subunits of AHAS III complement the catalytic subunit of the AHAS of B.

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Crystals have been grown of the carboxylesterase Est30 from Bacillus stearothermophilus by hanging-drop vapor diffusion using ammonium sulfate as precipitant. The crystals diffracted to better than 2.0 A resolution.

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A genomic library from a strain of Salmonella enterica serovar Paratyphi B that exhibits multiple drug resistance (MDR) was constructed in Escherichia coli. Two of the recombinant plasmids, pNOR5 and pNOR5, conferred resistance only to fluoroquinolones in E. coli, whereas the third, pNCTR4, conferred the MDR phenotype.

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