الفهرس 
Hypoxic-Ischemic Brain Injury in the NewbornOnly 14 pages are availabe for public view
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Abstract
Hypoxic ischemic encephalopathy is a major cause of neonatal mortality and irreversible damage to brain.
Severe, hypoxia may induce major deficit shortly after birth, while mild to moderate hypoxia may result in cognitive attention disorders later on in development .
A primary aim for clinical research is to identify as early as possible reliable indexes of brain injury in the hypoxic newborns to apply potential therapeutic interventions at the optimal time and to identify those infants at high risk for developmental delays and disabilities.
17-Beta estradiol is sex hormone(mislabeled the female hormone), it is also present in males and represents the major estrogen in humans.
Estradiol like other estradiols,is derived from cholesterol after side chain cleavage and utilizing the delta -5 pathway or the delta-4 pathway.
Estradiol has not only a critical impact on reproduction and sexual functioning but also affects another organ including bone structure. Estradiol is also produced in the brain and in arterial walls.
The steroid hormones 17 Beta-estradiol and progesterone are potent neuroprotective agents. 17 Beta-estradiol attenuates injury due to stroke (Toung et al.,1998) and in response to the deleterious effects of H/I.These differences extent to the subregional level, with findings of differential effects among the subfields of the hippocampus in response to H/I and excitotxicity (Xu et al .,1998).
17-Beta estradiol protects neurons from ischemic damage and attenuates accumulation of extracellular excitatory amino acid (Simpkins et al.,2004)
In cerebral ischemic, energy failure induces the release of various neurotransmitters, which provoke the catastrophic enzymatic processes leading to irreversible neuronal damage (Mintani et al.,1994).
Recently, estrogens have been found to be associated with a decreased risk and delayed onset and progression of stroke and enhanced recovery from numerous traumatic and chronic neurological and mental diseases (Garcia-Segura et al.,2001) .
Various lines of clinical and experimental evidence have shown that both endogenous and exogenous estrogens exert neuroprotective effects (Shao-Hua et al,.2003).
Protective effects of estrogens have been widely reported in different types of neuronal cells against different toxicity,and excitotoxicity (Green et al.,2000).
The aim of the present study is to detect Serum levels of 17-Betaestradiol in newborns with hypoxia and correlate the level with the severity of insult and thus predict the possible role of 17-Beta estradiol in identification of infants at high risk and the possible early therapeutic intervention.
The current study was a case-control study, conducted on 70 term neonates at Obstetrics and Gynecology Hospital Ain Shams University and cases admitted at N I C U.
All newborns were subjected to careful history taking, full clinical examination and laboratory investigations (Hb,CRP)and Serum 17-Beta estradiol levels determination.
The neonates in the present study were classified into two groups:
Patients group; and it included 32 full term neonates with evidence of hypoxia and were classified as grade 1 and 2 and 3.according to severity of hypoxia
Control group; and it included 38 healthy neonates.
Results:
There was highly statistically significant difference in serum level of 17-Beta estradiol in patients compared to controls and it was even higher in patients with severe hypoxia compared to patients with moderate and mild hypoxia
Also there was highly statistically significant difference in mean value of 17-Beta estradiol in patients with history of prolonged labor or abnormal suckling reflex, anemia, Apgar score at 1 and5 min.
There was highly statistically significant difference in mean value of 17-Beta estradiol in female when compared to male in controls but there was no statistically significant difference between mean value in males when compared to female in patient group, different prenatal and natal history in patient group, different neurological examination (level of consciousness, muscle tone, Moro reflex),chest,heart examination, CRP,gestational age and weight.
There was statistically significant higher S.17-Beta estradiol in patients with +ve seizures, weak stretch reflex and abdominal examination.
Assessment of the sensitivity and specificity of 17-Beta estradiol as marker for hypoxic insult was done and showed that it has 100% sensitivity and 84% specificity with a cut-off value 145 pg/ml.
from the results of the current study, we can conclude that 17-Beta estradiol level can be used as a diagnostic test having a high sensitivity and specificity for newborns with hypoxia, and its level increases with the increase in the severity of hypoxia, but its utility as a neuroprotective agent could not be proven.