الفهرس 
Toxicokinetics of OP compoundsOnly 14 pages are availabe for public view
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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.