Related Research Articles
A transient ischemic attack (TIA), commonly known as a mini-stroke, is a minor stroke whose noticeable symptoms usually end in less than an hour. TIA causes the same symptoms associated with strokes, such as weakness or numbness on one side of the body, sudden dimming or loss of vision, difficulty speaking or understanding language, slurred speech, or confusion.
Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism. Ischemia is generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue i.e. hypoxia and microvascular dysfunction. It also implies local hypoxia in a part of a body resulting from constriction. Ischemia causes not only insufficiency of oxygen, but also reduced availability of nutrients and inadequate removal of metabolic wastes. Ischemia can be partial or total blockage. The inadequate delivery of oxygenated blood to the organs must be resolved either by treating the cause of the inadequate delivery or reducing the oxygen demand of the system that needs it. For example, patients with myocardial ischemia have a decreased blood flow to the heart and are prescribed with medications that reduce chronotrophy and ionotrophy to meet the new level of blood delivery supplied by the stenosed vasculature so that it is adequate.
Infarction is tissue death (necrosis) due to inadequate blood supply to the affected area. It may be caused by artery blockages, rupture, mechanical compression, or vasoconstriction. The resulting lesion is referred to as an infarct (from the Latin infarctus, "stuffed into").
Stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.
Reperfusion injury, sometimes called ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue after a period of ischemia or lack of oxygen. The absence of oxygen and nutrients from blood during the ischemic period creates a condition in which the restoration of circulation results in inflammation and oxidative damage through the induction of oxidative stress rather than restoration of normal function.
Cerebral hypoxia is a form of hypoxia, specifically involving the brain; when the brain is completely deprived of oxygen, it is called cerebral anoxia. There are four categories of cerebral hypoxia; they are, in order of increasing severity: diffuse cerebral hypoxia (DCH), focal cerebral ischemia, cerebral infarction, and global cerebral ischemia. Prolonged hypoxia induces neuronal cell death via apoptosis, resulting in a hypoxic brain injury.
Doris Duke was an American billionaire tobacco heiress, philanthropist, and socialite. She was often called "the richest girl in the world". Her great wealth, luxurious lifestyle, and love life attracted significant press coverage, both during her life and after her death.
The ischemic (ischaemic) cascade is a series of biochemical reactions that are initiated in the brain and other aerobic tissues after seconds to minutes of ischemia. This is typically secondary to stroke, injury, or cardiac arrest due to heart attack. Most ischemic neurons that die do so due to the activation of chemicals produced during and after ischemia. The ischemic cascade usually goes on for two to three hours but can last for days, even after normal blood flow returns.
Brain ischemia is a condition in which there is insufficient bloodflow to the brain to meet metabolic demand. This leads to poor oxygen supply or cerebral hypoxia and thus leads to the death of brain tissue or cerebral infarction/ischemic stroke. It is a sub-type of stroke along with subarachnoid hemorrhage and intracerebral hemorrhage.
Ischemic colitis is a medical condition in which inflammation and injury of the large intestine result from inadequate blood supply. Although uncommon in the general population, ischemic colitis occurs with greater frequency in the elderly, and is the most common form of bowel ischemia. Causes of the reduced blood flow can include changes in the systemic circulation or local factors such as constriction of blood vessels or a blood clot. In most cases, no specific cause can be identified.
Myocardial stunning or transient post-ischemic myocardial dysfunction is a state of mechanical cardiac dysfunction that can occur in a portion of myocardium without necrosis after a brief interruption in perfusion, despite the timely restoration of normal coronary blood flow. In this situation, even after ischemia has been relieved and myocardial blood flow (MBF) returns to normal, myocardial function is still depressed for a variable period of time, usually days to weeks. This reversible reduction of function of heart contraction after reperfusion is not accounted for by tissue damage or reduced blood flow, but rather, its thought to represent a perfusion-contraction "mismatch". Myocardial stunning was first described in laboratory canine experiments in the 1970s where LV wall abnormalities were observed following coronary artery occlusion and subsequent reperfusion.
Ischemic preconditioning (IPC) is an experimental technique for producing resistance to the loss of blood supply, and thus oxygen, to tissues of many types. In the heart, IPC is an intrinsic process whereby repeated short episodes of ischaemia protect the myocardium against a subsequent ischaemic insult. It was first identified in 1986 by Murry et al. This group exposed anesthetised open-chest dogs to four periods of 5 minute coronary artery occlusions followed by a 5-minute period of reperfusion before the onset of a 40-minute sustained occlusion of the coronary artery. The control animals had no such period of “ischaemic preconditioning” and had much larger infarct sizes compared with the dogs that did. The exact molecular pathways behind this phenomenon have yet to be fully understood.
Disufenton sodium is a free radical trapping nitrone-based antioxidant compound that has been under development for several medical conditions.
Intestinal ischemia is a medical condition in which injury to the large or small intestine occurs due to not enough blood supply. It can come on suddenly, known as acute intestinal ischemia, or gradually, known as chronic intestinal ischemia. The acute form of the disease often presents with sudden severe abdominal pain and is associated with a high risk of death. The chronic form typically presents more gradually with abdominal pain after eating, unintentional weight loss, vomiting, and fear of eating.
Targeted temperature management (TTM) previously known as therapeutic hypothermia or protective hypothermia is an active treatment that tries to achieve and maintain a specific body temperature in a person for a specific duration of time in an effort to improve health outcomes during recovery after a period of stopped blood flow to the brain. This is done in an attempt to reduce the risk of tissue injury following lack of blood flow. Periods of poor blood flow may be due to cardiac arrest or the blockage of an artery by a clot as in the case of a stroke.
Nizofenone is a neuroprotective drug which protects neurons from death following cerebral anoxia. It might thus be useful in the treatment of acute neurological conditions such as stroke.
Acadesine (INN), also known as 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, AICA-riboside, and AICAR, is an AMP-activated protein kinase activator which is used for the treatment of acute lymphoblastic leukemia and may have applications in treating other disorders such as diabetes. AICAR has been used clinically to treat and protect against cardiac ischemic injury. The drug was first used in the 1980s as a method to preserve blood flow to the heart during surgery.
Eliprodil is an NMDA antagonist drug candidate which selectively inhibits the NR2B (GLUN2B) subtype NMDA receptor at submicromolar concentrations. Eliprodil failed a Phase III clinical trial for the treatment of acute ischemic stroke in 1996, sponsored by Synthélabo Recherche.
Mild total body hypothermia, induced by cooling a baby to 33-34°C for three days after birth, is nowadays a standardized treatment after moderate to severe hypoxic ischemic encephalopathy in full-term and near to fullterm neonates. It has recently been proven to be the only medical intervention which reduces brain damage, and improves an infant's chance of survival and reduced disability.
Remote ischemic conditioning (RIC) is an experimental medical procedure that aims to reduce the severity of ischaemic injury to an organ such as the heart or the brain, most commonly in the situation of a heart attack or a stroke, or during procedures such as heart surgery when the heart may temporary suffer ischaemia during the operation, by triggering the body's natural protection against tissue injury. Although noted to have some benefits in experimental models in animals, this is still an experimental procedure in humans and initial evidence from small studies have not been replicated in larger clinical trials. Successive clinical trials have failed to identify evidence supporting a protective role in humans.
References
- ↑ Lees, Kennedy R.; Zivin, Justin A.; Ashwood, Tim; Davalos, Antonio; Davis, Stephen M.; Diener, Hans-Christoph; Grotta, James; Lyden, Patrick; et al. (2006). "NXY-059 for Acute Ischemic Stroke". New England Journal of Medicine. 354 (6): 588–600. doi: 10.1056/NEJMoa052980 . PMID 16467546.
- ↑ Nita, DA; Nita, V; Spulber, S; Moldovan, M; Popa, DP; Zagrean, AM; Zagrean, L (2001). "Oxidative damage following cerebral ischemia depends on reperfusion – a biochemical study in rat". Journal of Cellular and Molecular Medicine. 5 (2): 163–70. doi:10.1111/j.1582-4934.2001.tb00149.x. PMC 6738122 . PMID 12067499.
- ↑ Article at Howarth Smith.com Archived March 8, 2006, at the Wayback Machine
- ↑ Cornell Law