Publications by authors named "Ahmed Raef"

Purpose: We aimed to evaluate the effect of cervical disc herniation (CDH) and lumbar disc herniation (LDH) on female sexual functioning before and after surgical intervention.

Methods: The current study was conducted from February 2022 to February 2023. A total of 100 sexually active female patients in their reproductive phase who were diagnosed with CDH and LDH based on physical examination and previous magnetic resonance imaging (MRI) results, as well as 50 healthy females, were enrolled.

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Background And Objectives: Prior to the mid-1980s, the treatment of choice for anal cancer was abdominoperineal resection. Currently, combined chemoradiation is the standard of care. Or objective was to analyze results of treatment for anal canal carcinoma treated with combined chemoradiation.

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Objective: Data concerning HPV infection in cervical cancer are globally lacking in Saudi Arabia. Therefore, the aim of this study was to assess HPV prevalence and genotypes' distribution in invasive cervical cancer in our patients to provide baseline information for screening and prevention.

Methods: The study included 100 paraffin-embedded cervical tumors.

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The clinical application of intensity modulated radiotherapy (IMRT) for adjuvant treatment of breast cancer has been the subject of increasing study in recent years. IMRT results in improved target coverage, reduced dose inhomogeneity within the breast, and reduced dose to the heart, lungs, and contralateral breast. However, this has been at the cost of larger volumes of low-dose radiation to these structures, thus increasing the theoretic risk for second malignancies.

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We wanted to describe a technique for the implementation of intensity-modulated radiotherapy (IMRT) with a real-time position monitor (RPM) respiratory gating system for the treatment of pleural space with intact lung. The technique is illustrated by a case of pediatric osteosarcoma, metastatic to the pleura of the right lung. The patient was simulated in the supine position where a breathing tracer and computed tomography (CT) scans synchronized at end expiration were acquired using the RPM system.

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The treatment of maxillary sinus carcinoma with forward planning can be technically difficult when the neck also requires radiotherapy. This difficulty arises because of the need to spare the contralateral face while treating the bilateral neck. There is considerable potential for error in clinical setup and treatment delivery.

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[reaction: see text] A chemoenzymatic synthesis of ADP-D-glycero-beta-D-manno-heptose (ADP-D,D-Hep) is described in which D,D-Hep 7-phosphate is converted to ADP-D,D-Hep by two biosynthetic enzymes. This strategy allows access to the 6''-deuterated analogue, which upon incubation with the epimerase showed complete retention of the isotopic label at the 6''-position. This provides evidence for a direct oxidation mechanism in which the hydride initially transferred to the NADP+ cofactor is subsequently returned to the same carbon in a nonstereospecific manner.

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The biosynthetic pathway of the red-pigmented antibiotic, prodigiosin, produced by Serratia sp. is known to involve separate pathways for the production of the monopyrrole, 2-methyl-3-n-amyl-pyrrole (MAP) and the bipyrrole, 4-methoxy-2,2'-bipyrrole-5-carbaldehyde (MBC) which are then coupled in the final condensation step. We have previously reported the cloning, sequencing and heterologous expression of the pig cluster responsible for prodigiosin biosynthesis in two Serratia sp.

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Purpose: The conventional single-isocenter and half-beam (SIHB) technique for matching supraclavicular fields with head-and-neck (HN) intensity-modulated radiotherapy (IMRT) fields is subject to substantial dose inhomogeneities from imperfect accelerator jaw/MLC calibration. It also limits the isocenter location and restricts the useful field size for IMRT. We propose a dynamic field-matching technique to overcome these limitations.

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Purpose: To evaluate the feasibility of dose-escalated para-aortic lymph node (PALN) intensity modulated radiation therapy (IMRT) in reducing the dose to bone marrow, bowel, spinal cord, and kidneys, compared with conventional radiation techniques of PALNs in patients with locally advanced cervical cancer and PALN metastases.

Methods And Materials: Computed tomography scans and MRI studies of 5 cervical cancer patients with PALN involvement were transferred to an IMRT treatment planning workstation (Eclipse/Helios) for image fusion and definition of target volumes and critical structures. The positive PALNs identified on fused computed tomography-magnetic resonance images were defined as the gross target volume (GTV), and the PALN region was defined as the planning target volume.

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ADP-l-glycero-d-manno-heptose 6-epimerase (AGME, RfaD) is a bacterial enzyme that is involved in lipopolysaccharide biosynthesis and interconverts ADP-beta-l-glycero-d-manno-heptose (ADP-l,d-Hep) with ADP-beta-d-glycero-d-manno-heptose (ADP-d,d-Hep). AGME is known to require a tightly bound NADP+ cofactor for activity and presumably employs a mechanism involving transient oxidation of the substrate. Four mechanistic possibilities are considered that involve transient oxidation at either C-7' ', C-6' ', or C-4' ' of the heptose nucleotide.

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Two analogues of porphobilinogen, the 6-methyl and 6,11-ethano derivatives, have been made by a new synthetic route and the 6-methyl analogue has proved to be the most potent inhibitor of hydroxymethylbilane synthase yet reported (Ki = 3 microM).

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