Table of Contents
What is Reoxygenation in radiobiology?
During the course of the treatment, some hypoxic cells become oxygenated. • If this was not there then the proportion of hypoxic cells should increase • This phenomenon, by which hypoxic cells become oxygenated after a dose of radiation, is termed reoxygenation.
What is Reoxygenation injury?
Reperfusion injury, sometimes called ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue (re- + perfusion) after a period of ischemia or lack of oxygen (anoxia or hypoxia).
What is re oxygenation?
Reoxygenation refers to the empirical observation that hypoxic regions in tumors may improve their oxygenation during fractionated radiotherapy.
What causes hypoxic cell injury?
Hypoxic injury results in an inadequate flow of nutrients and oxygen to the cell. If tissue perfusion continues to be insufficient, hypoxia occurs and the cell resorts to anaerobic metabolic pathways for energy production.
What is Reoxygenation what are the factors that affect Reoxygenation?
Disordered breathing events result in hypoxemia, reoxygenation (analogous to ischemic reperfusion), hypercapnia, and a host of neurohormonal abnormalities such as increased sympathetic activity, hypercoagulopathy, release of endothelin, abnormal endothelium-dependent vasodilatation, growth and apoptosis, activation of …
What are the 4 Rs of radiotherapy?
In general, success or failure of standard clinical radiation treatment is determined by the 4 R’s of radiobiology: repair of DNA damage, redistribution of cells in the cell cycle, repopulation, and reoxygenation of hypoxic tumor areas.
What is deoxygenation water?
Ocean warming-driven deoxygenation: Warmer ocean water holds less oxygen and is more buoyant than cooler water. This leads to reduced mixing of oxygenated water near the surface with deeper waters, which naturally contain less oxygen. As a result, less oxygen is available for marine life.
What is deoxygenation constant?
The result of the deoxygenation rate calculation gives the range of 0.06 to 0.08 per day. A typical value of the deoxygenation rate for the surface water is 0.10-0.23 per day16. The upstream water result is suitable for the typical condition of deoxygenation rate.
What is the most common cause of hypoxic injury?
In the United States, cardiac arrest is the most common cause of hypoxic brain injury. Other causes include traumatic vascular injuries; near-drowning; smoke inhalation or carbon monoxide poisoning; shock, including hemorrhagic and septic shock; drug overdoses; and acute lung injury.
Which part of the brain is most sensitive to hypoxia?
hippocampus
Besides its immediate effects, hypoxia causes delayed functional and metabolic disturbances which may even progress to cell death. The brain regions most sensitive to this type of injury are parts of the hippocampus, the dorsolateral caudate nucleus and the reticular nucleus of thalamus.
What is deoxygenation curve?
Deoxygenation curve: The rate of deoxygenation depends upon the amount of organic matter remaining to be oxidized at a given time as well as on the temperature of reaction, hence at given temperature, the curve showing depletion of DO with time i.e. deoxygenation curve is similar to the first stage BOD-curve.
What can radiotherapy be used for?
Radiation therapy (also called radiotherapy) is a cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors. At low doses, radiation is used in x-rays to see inside your body, as with x-rays of your teeth or broken bones.