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There are a number of methods to measure hypoxia in tissues; all have advantages and disadvantages. Three key methods that are relevant to the discussions in this paper are below (for reviews see Refs 142,143,144,145,146,147).
Hypoxia marker drugs
These drugs are 2-nitroimidazoles; after entering cells they undergo 1-2 electron reduction in cells and the reduced drug is a highly reactive free radical that binds to macromolecules, including proteins148. However, when oxygen is present, the drug is oxidized and reverts back to its original state, allowing it to diffuse out of the cell and eventually into the circulation. The rate of protein binding of the reduced drug increases exponentially with a decrease in partial pressure of O2, particularly below 10 mmHg144, 149. The presence of drug-protein adducts can be detected immunohistochemically using antibodies specific for the drug protein adduct. 18F-labelled versions of these drugs are also being developed for positron-emission tomography imaging150, 151.
Hypoxia marker proteins
As HIF1 upregulates the synthesis of many proteins, it has been proposed that identification of such proteins in tissues could be markers of hypoxia. Literally dozens of such proteins have been studied at the preclinical level and in clinical trials152. Some of the more promising endogenous markers include carbonic anhydrase IX (CA9), plasminogen activator inhibitor 1 (PAI1, also known as SERPINE), osteopontin and lysyl oxidase. Combinations of markers might prove to be better predictors of clinical outcome than any single marker153.
Oxygen electrodes and optical probes
Oxygen can be measured in any aqueous media using polarography. In principle, two electrodes are placed into the medium and a polarizing voltage of - 0.7 volts is applied across them. This voltage corresponds to the binding energy of outer shell electrons of oxygen. The electrons are captured by the cathode and the current generated is linearly proportional to oxygen concentration. In practice, the cathode is embedded into a needle that can be introduced into tissues and the anode is placed on the body surface. This technique has been used extensively in preclinical and clinical studies; the presence of hypoxia is an independent predictive factor for poor prognosis in many different tumour types154. Optical probes have also been developed: these are implanted into tissues and contain a fluorochrome that emits fluorescent light with a certain decay rate when illuminated. The rate of fluorescent light decay is proportional to the oxygen concentration in the region of measurement. These probes yield data similar to that of the oxygen electrode6.
What else can I help you with?
What is cellular oxygen deficiency?
Cellular oxygen deficiency, also known as hypoxia, occurs when there is inadequate oxygen supply to the cells. This can lead to impaired cellular function and damage, affecting the normal functioning of tissues and organs. Severe or prolonged oxygen deficiency can cause tissue injury and organ failure.
Does oxygen have an excess or a deficiency of electrons?
Oxygen tends to gain two electrons to fill its outer shell, resulting in a deficiency of electrons.
What organ system detects changes in the environment?
B I U S x x 123
What would be the consequence of deficiency of hemoglobin in your bodies?
if there would be low haemoglobin levels in our body then our body will lack oxygen too as oxygen is transported to all the parts of our body through the blood. Deficient haemoglobin can lead to anaemia also.
What organ in the human body uses 40 percent of the oxygen in your blood?
The brain consumes 40% of the oxygen in your blood.
What is cellular oxygen deficiency?
Cellular oxygen deficiency, also known as hypoxia, occurs when there is inadequate oxygen supply to the cells. This can lead to impaired cellular function and damage, affecting the normal functioning of tissues and organs. Severe or prolonged oxygen deficiency can cause tissue injury and organ failure.
What condition is deficiency of oxygen?
The deficiency of oxygen is called hypoxia, which can occur when there is a decrease in the oxygen supply to tissues in the body. This can lead to symptoms such as shortness of breath, confusion, and eventually organ damage if left untreated. Treatment usually involves providing supplemental oxygen to the individual.
What detects a stimulus?
sense organ
Which organ detects changes in the environment?
Sense Organs
What organ system detects environmental changes?
The nervous system.
What is the organ called that detects heat in snakes?
Heat pit
Patients with what deficiency are particularly at risk in contracting deep organ candidiasis?
Patients with granulocytopenia (deficiency of white blood cells) are particularly at risk for deep organ candidiasis.
What is a deficiency of blood through an organ or body part?
Hypoperfusion!
Does oxygen have an excess or a deficiency of electrons?
Oxygen tends to gain two electrons to fill its outer shell, resulting in a deficiency of electrons.
What is the lack of the ability of the body to carry oxygen may be due to a deficiency?
A lack of the ability of the body to carry oxygen may be due to a deficiency in
Golgi tendon organ detects the magnitude of mechanical stress at the musculotendinous junction?
True
Hypoxia is the result?
a deficiency in oxygen intake.
