Cairo University

About: Cairo University is a education organization based out in Giza, Egypt. It is known for research contribution in the topics: Population & Medicine. The organization has 33532 authors who have published 55581 publications receiving 792654 citations. The organization is also known as: Fuad I University & King Fuad I University.

Development and Validation of a Novel Acute Myeloid Leukemia-Composite Model to Estimate Risks of Mortality.

Abstract: Importance To our knowledge, this multicenter analysis is the first to test and validate (1) the prognostic impact of comorbidities on 1-year mortality after initial therapy of acute myeloid leukemia (AML) and (2) a novel, risk-stratifying composite model incorporating comorbidities, age, and cytogenetic and molecular risks. Objective To accurately estimate risks of mortality by developing and validating a composite model that combines the most significant patient-specific and AML-specific features. Design, Setting, and Participants This is a retrospective cohort study. A series of comorbidities, including those already incorporated into the hematopoietic cell transplantation–comorbidity index (HCT-CI), were evaluated. Patients were randomly divided into a training set (n = 733) and a validation set (n = 367). In the training set, covariates associated with 1-year overall mortality at a significance level of P < .10 constructed a multivariate Cox proportional hazards model in which the impact of each covariate was adjusted for that of all others. Then, the adjusted hazard ratios were used as weights. Performances of models were compared using C statistics for continuous outcomes and area under the curve (AUC) for binary outcomes. Exposures Initial therapy for AML. Main Outcomes and Measures Death within 1 year after initial therapy for AML. Results A total of 1100 patients, ages 20 to 89 years, were treated for AML between January 1, 2008, and December 31, 2012, at 5 academic institutions specialized in treating AML; 605 (55%) were male, and 495 (45%) were female. In the validation set, the original HCT-CI had better C statistic and AUC estimates compared with the AML comorbidity index for prediction of 1-year mortality. Augmenting the original HCT-CI with 3 independently significant comorbidities, hypoalbuminemia, thrombocytopenia, and high lactate dehydrogenase level, yielded a better C statistic of 0.66 and AUC of 0.69 for 1-year mortality. A composite model comprising augmented HCT-CI, age, and cytogenetic/molecular risks had even better predictive estimates of 0.72 and 0.76, respectively. Conclusions and Relevance In this cohort study, comorbidities influenced 1-year survival of patients with AML, and comorbidities are best captured by an augmented HCT-CI. The augmented HCT-CI, age, and cytogenetic/molecular risks could be combined into an AML composite model that could guide treatment decision-making and trial design in AML. Studying physical, cognitive, and social health might further clarify the prognostic role of aging. Targeting comorbidities with interventions alongside specific AML therapy might improve survival.

Ocular ciprofloxacin hydrochloride mucoadhesive chitosan-coated liposomes

Abstract: The aim of this work is to improve the ocular bioavailability of ciprofloxacin hydrochloride (CPX) through the preparation of ocular mucoadhesive chitosan (CS)-coated liposomes. Liposomes were prepared by the thin film hydration technique, using different molar ratios of L-α-phosphatidylcholine (PC), cholesterol (CH), stearylamine (SA) and dicetyl phosphate (DP). CS was used to coat the optimal liposomal formulae. The prepared formulae were characterized regarding encapsulation efficiency (%EE), particle size, physical morphology and in vitro drug release. The in vivo characterization of the prepared formulae was performed through evaluating the level of CPX in the external eye tissue of nine albino rabbits. Results showed an alteration in release rate and %EE of CPX from liposomal formulae upon varying the molar ratios of the lipid bilayer composition. The optimal liposomal formulae F1 (10:0, PC:CH), F12 (10:0:0.5, PC:CH:SA) and F15 (10:0:1, PC:CH:DP), showed % EE of 38.5 ± 2.10, 39.65 ± 1.85 and 30.05 ±...

Effect of metallurgical parameters on the hardness and microstructural characterization of as-cast and heat-treated 356 and 319 aluminum alloys

Abstract: The present study was undertaken to investigate the effect of metallurgical parameters on the hardness and microstructural characterization of as-cast and heat-treated 356 and 319 alloys, with the aim of adjusting these parameters to produce castings of suitable hardness and Fe-intermetallic volume fractions for subsequent use in studies relating to the machinability of these alloys. By measuring the amount of Fe- and Cu-intermetallics formed and the changes in the eutectic Si particle characteristics resulting from alloying additions (Fe, Mn, Mg), Sr-modification, and heat treatment of the 356 and 319 alloys, and the corresponding hardness values, it was possible to determine which conditions or metallurgical parameters yielded the required Fe-intermetallic volume fractions of 2 and 5% and hardness levels of 85 and 115 BHN. These levels conform to the most common levels observed in the commercial application of these alloys. The 356 and 319 alloys were examined in the as-cast and heat-treated conditions, using different combinations of grain refining, Sr-modification, and alloying additions. Aging treatments were carried out at 155, 180, 200, and 220 °C for 4 h, followed by air cooling, as well as at 180 and 220 °C for 2, 4, 6, and 8 h to determine conditions under which the specified hardness levels of 85 and 115 HBN could be obtained. Hardness measurements were carried out using a Brinell hardness tester. Peak hardness was observed in the 356 and 319 alloys at different aging conditions, depending upon the Fe-intermetallic type present in the alloy and whether the alloy was modified or not. Aging at 220 °C revealed a hardness peak at 2 h aging time in both 356 and 319 alloys. Addition of Mg to 319 alloys produced a remarkable increase in hardness at all aging temperatures. This may be explained on the basis of the combined effect of Cu- and Mg-intermetallics in the 319 alloys, where hardening during aging occurs by the cooperative precipitation of Al 2 Cu and Mg 2 Si phase particles [P. Ouellet, F.H. Samuel, J. Mater. Sci. 34 (1999) 4671–4697; P.N. Crepeau, S.D. Antolovich, J.A. Worden, AFS Trans. 98 (1990) 813–822]. Iron-intermetallic volume fraction measurements were carried out on polished specimens of the 356 and 319 alloys using electron probe microanalysis, for both as-cast and heat-treated conditions. Copper-intermetallic volume fractions were also measured for the 319 alloys to determine the amount of undissolved CuAl 2 phase. It was observed that the unmodified alloys displayed higher Fe-intermetallic surface fractions than the modified alloys. The copper-intermetallic surface fractions, on the other hand, were higher in the Sr-modified alloys than the unmodified alloys. These observations may be attributed to the effect of Sr on (a) the dissolution and fragmentation of the β-Fe-intermetallics in the matrix, the solution heat treatment also contributing to this effect; (b) severe segregation of Al 2 Cu and Al 2 MgCu phases in areas away from the eutectic Si regions, slowing down the dissolution of the Al 2 Cu phase during solution treatment; (c) altering the precipitation sequence of α-Al 15 (Fe, Mn) 3 Si 2 from post-dendritic to pre-dendritic, the latter being expected to improve the alloy strength due to its precipitation within the α-Al dendrites.