58 research outputs found
Pleiotropic Effects of Tetracyclines in the Management of COVID-19: Emerging Perspectives
Coronavirus disease 2019 (COVID-19) is a global infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Approximately 15% of severe cases require an intensive care unit (ICU) admission and mechanical ventilation due to development of acute respiratory distress syndrome (ARDS). Tetracyclines (TCs) are a group of bacteriostatic antibiotics, like tetracycline, minocycline, and doxycycline, effective against aerobic and anaerobic bacteria as well as Gram-positive and Gram-negative bacteria. Based on available evidences, TCs may be effective against coronaviruses and thus useful to treat COVID-19. Thus, this review aims to provide a brief overview on the uses of TCs for COVID-19 management. SARS-CoV-2 and other coronaviruses depend mainly on the matrix metalloproteinases (MMPs) for their proliferation, cell adhesion, and infiltration. The anti-inflammatory mechanisms of TCs are linked to different pathways. Briefly, TCs inhibit mitochondrial cytochrome c and caspase pathway with improvement of lymphopenia in early COVID-19. Specifically, minocycline is effective in reducing COVID-19–related complications, through attenuation of cytokine storm as apparent by reduction of interleukin (IL)-6, IL-1, and tumor necrosis factor (TNF)-a. Different clinical trials recommend the replacement of azithromycin by minocycline in the management of COVID-19 patients at high risk due to two main reasons: 1) minocycline does not prolong the QT interval and even inhibits ischemia-induced arrhythmia; 2) minocycline displays synergistic effect with chloroquine against SARS-CoV-2. Taken together, the data presented here show that TCs, mainly doxycycline or minocycline, may be potential partners in COVID-19 management, derived pneumonia, and related complications, such as acute lung injury (ALI) and ARDS.The authors thank all members of the College of Medicine, Al-Mustansiyria University. NC-M acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017)
The global burden of cancer attributable to risk factors, 2010-19: a systematic analysis for the Global Burden of Disease Study 2019
Multi-criteria decision analysis with goal programming in engineering, management and social sciences: a state-of-the art review
Macular microstructure and visual acuity after macula-off retinal detachment repair by 23-gauge vitrectomy plus silicone endotamponade
Essam Elmatbouly Saber, Ahmed Sherin Mostafa Bayoumy, Mohamed Nagy Elmohamady, Hussam Mustafa Faramawi Department of Opthalmology, Faculty of Medicine, Benha University, Qaliopia, Egypt Objectives: To study the macular microstructural changes and their relationship to visual acuity (VA) following primary vitrectomy and silicone tamponade for retinal detachment. Patients and methods: A total of 40 cases with macula-off rhegmatogenous retinal detachment underwent 23-gauge vitrectomy with silicone oil tamponade. Cases with open globe injury and other ocular pathology were excluded. Optical coherence tomography (OCT) imaging of the macula was done about 3 and 6 months postoperatively. OCT macular microstructural changes were recorded and correlated to VA. Results: A total of 36 eyes were evaluated by statistical analysis. The best-corrected VA (BCVA) improved in 35 patients (97.2%) and remained unchanged in one patient (2.8%). Patients were divided into two groups based on 6-month postoperative BCVA: group I with 6-month postoperative BCVA of <1 LogMAR and group II with 6-month postoperative BCVA of ≥1 LogMAR. No disruption of retinal microstructure occurred in 70% of cases in group I. Mild disruption was found in 30% of group I and 25% of group II, whereas severe disruption was found in 75% of group II cases. Epiretinal membrane formed early in three eyes in group II and late in two eyes in group I. Conclusion: Macular microstructural changes detected by OCT is directly correlated to visual outcomes of retinal detachment repair. Keywords: retinal detachment, vitrectomy, silicone oil, OCT, ellipsoid zone, ER
Hybrid Consensus-Based Formation Control of Nonholonomic Mobile Robots
In this chapter, a hybrid consensus-based formation controller is designed for mobile robots. First, omnidirectional (holonomic) robots are considered in the controller development to create a hybrid automaton, which drives the robots to their goal positions while maintaining a specified formation. The controller consists of two discrete modes, each with continuous dynamics: a regulation mode and a formation keeping mode. The controller in the regulation mode is designed to drive the robot to a goal position, while the formation keeping controller ensures that the robots achieve a specified geometric formation prior to reaching their goal-position. The proposed approach is subsequently extended to include formation control of nonholonomic mobile robots. Lyapunov methods are used to demonstrate that the formation errors converge to a small bounded region around the origin; moreover, the size of the bound can be adjusted by using the switching conditions. Convergence to goal position while in formation is also demonstrated in the same Lyapunov analysis, and simulation results verify the theoretical conjectures
Nonclinical Aspects of Biopharmaceutical Development: Discussion of Case Studies at a PhRMA-FDA Workshop
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