Publications by authors named "Guirguis R"

Background: Invasive dental treatment in patients exposed to antiresorptive and antiangiogenic drugs can cause medication-related osteonecrosis of the jaw (MRONJ). Currently, the exact pathogenesis of this disease is unclear.

Methods: In March 2022, Medline (Ovid), Embase (Ovid), Scopus, and Web of Science were screened to identify eligible in vitro studies investigating the effects of antiresorptive and antiangiogenic compounds on orally derived cells.

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The COVID-19 crisis presented teachers and families with the challenge of educating young children online. This study explored the experiences with virtual education of 51 parents and 53 teachers of young children. The results have shown that families and educators were aligned in their goals for early childhood education.

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Background: Biliary complications (BCs) after liver transplantation (LT) remain a considerable cause of morbidity, mortality, increased cost, and graft loss.

Aim: To investigate the impact of BCs on chronic graft rejection, graft failure and mortality.

Methods: From 2011 to 2016, 215 adult recipients underwent right-lobe living-donor liver transplantation (RT-LDLT) at our centre.

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Background: Despite significant advancements in liver transplantation (LT) surgical procedures and perioperative care, post-LT biliary complications (BCs) remain a significant source of morbidity, mortality, and graft failure. In addition, data are conflicting regarding the health-related quality of life (HRQoL) of LT recipients. Thus, the success of LT should be considered in terms of both the survival and recovery of HRQoL.

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Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), became a pandemic in early 2020. Lateral flow immunoassays for antibody testing have been viewed as a cheap and rapidly deployable method for determining previous infection with SARS-CoV-2; however, these assays have shown unacceptably low sensitivity. We report on nine lateral flow immunoassays currently available and compare their titer sensitivity in serum to a best-practice enzyme-linked immunosorbent assay (ELISA) and viral neutralization assay.

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The United Nations Population Fund (UNFPA) and the United States Agency for International Development (USAID) DELIVER PROJECT work together to strengthen public health commodity supply chains by standardizing bar coding under a single set of global standards. From 2015, UNFPA and USAID collaborated to pilot test how tracking and tracing of bar coded health products could be operationalized in the public health supply chains of Ethiopia and Pakistan and inform the ecosystem needed to begin full implementation. Pakistan had been using proprietary bar codes for inventory management of contraceptive supplies but transitioned to global standards-based bar codes during the pilot.

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Purpose: The diagnosis of hip osteoarthritis is often complicated by co-existing pathology in the knee and spine, and mismatch between clinical and radiological signs. Temporary pain relief from a local anaesthetic injection into the hip joint has been reported to help localise symptoms, reducing the risk of unnecessary surgery being performed. We hypothesize that good surgical outcome is predicted by good analgesia following diagnostic injection, and that alternative pathology is present when there is no response to injection.

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Neurodegenerative disorders such as prion diseases and Alzheimer's disease (AD) are characterized by neuronal dysfunction and accumulation of amyloidogenic protein. In vitro studies have demonstrated that these amyloidogenic proteins can induce cellular oxidative stress and therefore may contribute to the neuronal dysfunction observed in these illnesses. Although the neurotoxic pathways are not fully elucidated, recent studies in AD have demonstrated up-regulation of caspases in neurons treated with amyloid beta (Abeta) peptide, suggesting involvement of apoptotic processes.

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Purpose: The objective of this in-vitro study was to measure and compare microleakage around preventive resin restorations prepared conventionally or with air abrasion, in the presence or absence of acid etching.

Methods: One hundred extracted human non carious molars were assigned to each of four groups. Group A: fissures opened with a high speed handpiece, etched, and restored with composite and sealant.

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We have studied the role of combined measurements of tumor collagenase-stimulating factor (TCSF) and tumor autocrine motility factor (TAMF) in 83 first morning voids and 24-hour specimens in patients with bladder and renal cancer and control subjects. TCSF and TAMF were measured by immunoabsorption assay and motility test utilizing modified Boyden chamber. The mean concentrations of urinary TCSF and TAMF from cancer patients (n = 32) were 4- to 5-fold higher than those from benign conditions (n = 70).

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The metastasis of malignant tumour cells depends on their rapid replication, and their ability to adhere to the matrix of a biological barrier such as basement membrane, to degrade the matrix, and to migrate through this more permeable barrier. Secreted enzymes, including the cysteine proteinases cathepsins B and L, are known to degrade basement membrane components. Using a barrier-free substratum we studied the possible role of cysteine proteinases in influencing the motility per se of metastatic cells.

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Over the past several years, many tumor markers, including cell surface antigens, T-antigen, ras p55, and ras p52 proteins, have been studied as potential tumor markers of bladder cancer. The lack of specificity and inconsistency of these markers led us to develop a new method for studying the urinary excretion of autocrine motility factor (uAMF) and tumor cell collagenase stimulating factor (TCSF) in 24-hour and first morning voided specimens. AMF is a glycoprotein secreted by the malignant cells and is responsible for cell locomotion, a key event in invasion and metastases of the malignant cells.

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The tumor cell laminin receptor is a cell-surface protein that binds laminin with high affinity (Kd = 1.0 nM). The putative ligand-binding domain of the laminin receptor has been molecularly cloned and sequenced.

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Cell locomotion is an essential requirement for invasion and metastasis of malignant cells. We have previously described the characterization of a 50-kilodalton autocrine motility factor (AMF), a cytokine that stimulates motility in human tumor cells. In this study, we investigated the elaboration of this factor in vivo by human bladder carcinoma and in vitro by a cultured transitional cell carcinoma (TCC) of the bladder cell line T24P.

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Cancer invasion and metastases is a complex multistep process. In order for a tumor cell to successfully traverse all the steps of this process and initiate a metastatic colony, it must express the right combination of gene products. Such gene products may include proteins which regulate cell interaction with the basement membrane and cell motility.

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Cancer invasion and metastases is a complex multistep process. In order for a tumor cell to successfully traverse all the steps of this process and initiate a metastatic colony, it must express the right combination of gene products. Such gene products may include proteins which regulate cell interaction with the basement membrane and cell motility.

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Cancer invasion and metastases is a complex multi-step process. In order for a tumor cell to successfully traverse all the steps of this process and initiate a metastatic colony, it must express the right combination of gene products. Such gene products may include proteins which regulate cell interaction with the basement membrane and cell motility.

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Pseudopodia protrusion is a prominent feature of actively motile cells in vitro and invading tumour cells in vivo; however, the function and regulation of pseudopodia are poorly understood. Tumour autocrine motility factor (AMF) represents a new class of cytokines which are secreted by tumour cells and embryonic cells and induce random motility in the producer cells or in heterologous cells with appropriate receptors. Here we report that a major effect of this factor is to induce the extension of cell pseudopodia before cell translocation.

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The human melanoma cell line, A2058, has previously been shown to respond to an autocrine motility factor (AMF). We have studied biochemical pathways that may be involved in the generation of such a motile response. Pertussis toxin (PT) caused a profound, rapid decrease in stimulated motility that was both dose and time-dependent.

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