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Abstract The word ‘pesticide’ literally means an agent used to kill an undesirable organism. In the amended United States Federal Insecticide, Fungicide and Rodenticide, the definition of an ‘economic poison’ or pesticide was expanded to include any substance or mixture of substances intended for preventing, destroying, repelling any pest ”insect rodent, nematode, fungus, weed, other forms of aquatic plant” (Viswanathan et al., 2015). Organophosphorus compounds are the most commonly used insecticides to control agricultural, household and structural pests. They are largely used due to their effectiveness against variety of pests. The easy availability with lack of knowledge about its serious consequences resulting in increased its accidental and suicidal poisoning (Banerjee et al., 2014). According to the World Health Organization’s estimate, three million cases of Organophosphorus compounds poisoning occur every year, resulting in more than 250,000 deaths. This number also accounts for a substantial fraction of the almost 900,000 people worldwide who die by suicide every year (Soltaninejad and Shadnia, 2014). Exposure to organophosphorus compounds leads to inhibition of cholinesterase enzyme with subsequent accumulation of acetylcholine at synapses causing overstimulation of muscarinic and nicotinic receptors leading to central and peripheral manifestations (Sawamotoet al., 2014). Many patients, following acute exposure to organophosphorus compounds, will develop muscle weakness and paralysis especially in severe exposures, and patients will require prolonged ventilatory support in the intensive care unit and patients die because of respiratory failure. Introduction and Aim of the Work 2 The neurological manifestations have therefore been a primary focus of interest (Birdet al., 2016). Three different types of paralysis are recognized based largely on the time of occurrence and their different pathophysiology: Type I paralysis or acute paralysis, type II paralysis or Intermediate syndrome (IMS) and type III paralysis or organophosphate induced delayed polyneuropathy (OPIDP) (Latronico and Bolton, 2011). The Acute physiology and chronic health evaluation II (APACHE II) score was calculated from 12 routine physiological and laboratory measurements made during the first 24 h of admission. The score for each parameter was assigned from 0 to 4, with 0 being normal and four being the most abnormal. The sum of these values were added to a mark adjusting for patient age and a mark adjusting for chronic health problems to arrive at the APACHE II score. The measurement was made during the first 24 h following admission and resulted in an integer point score between 0 and 71(Söyüncü and Bektaþ, 2011). Neuron Specific Enolase (NSE) is a glycolytic enzyme family (enolases), and it is a dimeric form composed of two subunits that is found primarily in the cytoplasm of neurons, but also in peripheral neuroendocrine cells and in certain rare tumors, such as small cell lung cancer, neuroblastoma and melanoma. NSE is passively released by cell destruction only – it is not actively secreted into the extracellular space. (Rech et al., 2006) (Borg et al., 2012). Increased concentration of NSE can be measured in the cerebrospinal fluid (CSF) and in peripheral blood after neuronal damage and provides a reliable laboratory indicator of the degree of brain cell Introduction and Aim of the Work 3 damage and may allow for early prediction of outcome (El-Maraghi et al., 2013). Neurofilament light (NFL) is a CNS-enriched protein, abundantly expressed in the long myelinated subcortical white matter axons, together with the neurofilament medium (NFM) and heavy (NFH) subunits. NFL is one of the scaffolding proteins of the neural cytoskeleton, with important roles in axonal and dendritic branching and growth (Zetterberg et al., 2013). When neurons or axons degenerate, neurofilament proteins are released into the cerebrospinal fluid or blood. Immunoassays of neurofilament light protein (NFL) in cerebrospinal fluid and plasma act as indicator of axonal damage in neurological disorders (Jonsson et al., 2010). Aim of The Work The aim of this study is to measure the level of Neuron Specific Enolase (NSE) and Neurofilament Light Protein (NFL) in patients with acute Organophosphorus poisoning and to detect their usefulness as diagnostic and prognostic markers for organophosphorus-induced neurotoxicty. |