Georgetown University

About: Georgetown University is a education organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Population & Cancer. The organization has 23377 authors who have published 43718 publications receiving 1748598 citations. The organization is also known as: GU & Georgetown.

Bi-polar electrosurgical instruments and methods of making

Abstract: Bipolar surgical instruments for simultaneously cutting and coagulating tissue are provided that feature increased manufacturability and durability, reduced component cost and reduced assembly requirements. The bipolar instruments include opposite polarity electrodes isolated by a layer of electrical insulation deposited and specially prepared to reduce electrical breakdown and increase smoothness. A pivot pin connecting the electrodes is impregnated with hydrophobic material, and organic materials are generally avoided in the components and manufacture of the instruments. A simplified design for an endoscopic bipolar instrument is also provided to reduce cost and improve manufacturability and durability of such devices.

Mechanisms and clinical applications of the vacuum-assisted closure (VAC) Device: a review.

Abstract: The use of sub-atmospheric pressure dressings, available commercially as the vacuum-assisted closure (VAC) device, has been shown to be an effective way to accelerate healing of various wounds. The optimal sub-atmospheric pressure for wound healing appears to be approximately 125mm Hg utilizing an alternating pressure cycle of 5 minutes of suction followed by 2 minutes off suction. Animal studies have demonstrated that this technique optimizes blood flow, decreases local tissue edema, and removes excessive fluid from the wound bed. These physiologic changes facilitate the removal of bacteria from the wound. Additionally, the cyclical application of sub-atmospheric pressure alters the cytoskeleton of the cells in the wound bed, triggering a cascade of intracellular signals that increases the rate of cell division and subsequent formation of granulation tissue. The combination of these mechanisms makes the VAC device an extremely versatile tool in the armamentarium of wound healing. This is evident in the VAC device’s wide range of clinical applications, including treatment of infected surgical wounds, traumatic wounds, pressure ulcers, wounds with exposed bone and hardware, diabetic foot ulcers, and venous stasis ulcers. VAC has also proven useful in reconstruction of wounds by allowing elective planning of the definitive reconstructive surgery without jeopardizing the wound or outcome. Furthermore, VAC has significantly increased the skin graft success rate when used as a bolster over the freshly skin-grafted wound. VAC is generally well tolerated and, with few contraindications or complications, is fast becoming a mainstay of current wound care.

Chemistry and Antihypertensive Effects of Tempol and Other Nitroxides

Abstract: Nitroxides can undergo one- or two-electron reduction reactions to hydroxylamines or oxammonium cations, respectively, which themselves are interconvertible, thereby providing redox metabolic actions. 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol) is the most extensively studied nitroxide. It is a cell membrane-permeable amphilite that dismutates superoxide catalytically, facilitates hydrogen peroxide metabolism by catalase-like actions, and limits formation of toxic hydroxyl radicals produced by Fenton reactions. It is broadly effective in detoxifying these reactive oxygen species in cell and animal studies. When administered intravenously to hypertensive rodent models, tempol caused rapid and reversible dose-dependent reductions in blood pressure in 22 of 26 studies. This was accompanied by vasodilation, increased nitric oxide activity, reduced sympathetic nervous system activity at central and peripheral sites, and enhanced potassium channel conductance in blood vessels and neurons. When administered orally or by infusion over days or weeks to hypertensive rodent models, it reduced blood pressure in 59 of 68 studies. This was accompanied by correction of salt sensitivity and endothelial dysfunction and reduced agonist-evoked oxidative stress and contractility of blood vessels, reduced renal vascular resistance, and increased renal tissue oxygen tension. Thus, tempol is broadly effective in reducing blood pressure, whether given by acute intravenous injection or by prolonged administration, in a wide range of rodent models of hypertension.

Legitimacy, Interest Group Pressures, and Change in Emergent Institutions: The Case of Foreign Investors and Host Country Governments

Abstract: We offer a simple model of policy making, emphasizing socialization and limits on human cognition to explicate mechanisms of change in emergent (as opposed to established) institutions. Emergent institutions are more susceptible to change, and their opponents may use frames or existing reference points to illustrate inconsistency with prevailing notions of legitimacy. Broader institutional structures and specific organizational characteristics moderate pressure for change. This perspective has novel implications for strategy and policy design.