الفهرس 
An investment in knowledgeOnly 14 pages are availabe for public view
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Abstract
Biomarkers are characteristic biological properties that can be detected, and measured, in parts of the body, like the blood or tissue. Biomarkers can be specific cells, molecules, or genes, gene products, enzymes, or hormones. Complex organ functions or general characteristic changes in biological structures can also serve as biomarkers.
They may indicate either normal or diseased processes in the body. Although the term biomarker is relatively new, biomarkers have been used since antiquity. For example, body temperature is a well-known biomarker for fever. Blood pressure is used to determine the risk of stroke i.e. a biomarker for stroke.
Biomarkers of toxicity are chemicals, metabolites, susceptibility characteristics, or changes in the body that relate the exposure of an organism to a chemical. They have the ability to identify if an exposure has occurred the route of exposure, the pathway of exposure or the resulting effects of the exposure.
Biomarkers of toxicity are generally classified into biomarkers of exposure, effect and susceptibility.
Biomarkers of exposure are the actual chemicals, or chemical metabolites, that can be measured in the body or in body excreta to determine different characteristics of a person’s exposure. For example, a person’s blood can be tested to see the levels of lead and therefore determine the exposure.
Biomarkers of effect are the quantifiable changes that an individual endures which indicates an exposure to a compound and may indicate a resulting health effect. For example, the inhibition of AChE caused by organophosphorus compounds or carbamate pesticides.
Biomarkers of susceptibility are indicators of the natural characteristics of an organism that make it more susceptible to the effects of an exposure to a chemical. For example, paraoxonase (PON1) enzyme polymorphism in cases of organophosphorus toxicity.
Ideal biomarkers must be evaluated in terms of their ability to predict and quantify exposure and dose. There are certain properties that are desirable when linking a biomarker with an exposure. These include high specificity and sensitivity, linear relationship across time, strong correlation with a health effect, inexpensive study, reliability and consistency.
On the other hand a lot of pitfalls should be avoided like, measurement errors, bias, misinterpretation, high cost and being unacceptable by ethical committees or subjects.
After the discovery of the human genomic map, recently, new technologies were used in the field of biomarkers of toxicity the most important of which are the toxicoproteomics, toxicogenomics, and metabolomics and it seems that in the coming few years it will be the area of innovation in biomarkers research.
Toxicologists all over the world performed great efforts in the past two decades, trying to specify useful biomarkers for the most common intoxications like OPC, acetaminophen, iron, scorpion sting and carbon monoxide poisoning, in order to help physicians in both diagnosis and follow up of these cases.
For OPC many studies adopted B-Glucuronidase enzyme as a biomarker of severity for these compounds, Scientists also agreed on considering paraoxonase enzyme as a biomarker of susceptibility for the same compounds.
For cases of Acetaminophen many new biomarkers were introduced, the most important were Taurine enzyme, serum protein adducts, microRNA and cytochrome C.
Serum Hepcidin level was proved to be a very sensitive biomarker for acute iron intoxication.
Measurements of catecholamines, neuropeptide Y (NPY), endothelin-1 (ET-1) and atrial natriuretic peptide (ANP) as well as serum Troponin I (cTnI) and Interleukin-8(IL-8) are all considered important biomarkers in cases of scorpion envenomation.
In cases of carbon monoxide poisoning, S100 beta, neuron specific enolase, activated neutrophils and CSF abnormalities are all considered as useful biomarkers.
Before usage of any biomarker, ethical considerations should be fulfilled both in research and application.
Living in the era of evidence based medicine every effort should be done for proper validation and quality assurance of all new biomarkers.
In the recent few years, the increased pace of terroristic attacks all over the world, raised the importance of finding new and reliable biomarkers of toxicity, concerning the chemical warfare agents. Supported by the most powerful countries like USA the researches in this field showed an accelerating pace using the most recent technologies like, Omics technology and nanotechnology.
A toxic tort is a special type of personal injury lawsuit in which the plaintiff claims that exposure to a chemical caused the plaintiff’s injury or disease, biomarkers may play a very important role in these lawsuits to prove or deny exposure and effect of those chemicals on the plaintiff.