Effect of phototherapy on oxidant/antioxidant status: a randomized controlled trial.

In order to evaluate the effect of different types of phototherapy on oxidant/antioxidant status in hyperbilirubinemic neonates, an interventional randomized control trial was conducted on 120 neonates ≥35 weeks' gestational age with indirect hyperbilirubinemia reaching phototherapy level. This study is registered with ClinicalTrials.gov as NCT03074292. Neonates were assigned to three groups; 40 neonates received conventional phototherapy, 40 received intensive phototherapy and 40 received blue light-emitting diodes (LED) phototherapy. Complete blood count (CBC), total serum bilirubin (TSB), total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO), copper (Cu), zinc (Zn), and iron (Fe) levels were measured before and 24 hours after phototherapy. TSB decreased postphototherapy in all three groups (p < .05 for all), with significantly lower levels following intensive and LED phototherapy compared to conventional phototherapy (p < .05 for both). TAC decreased postphototherapy in the three groups (p < .05 for all). MDA and NO increased postphototherapy (p < .05 for all), with the intensive phototherapy group having the highest levels followed by the conventional while LED phototherapy group showed the lowest levels in comparison to the other groups (p < .05). Cu, Zn and Fe increased postphototherapy in all three groups (p < .05 for all). Positive correlations were found between postphototherapy TSB with TAC, Cu and Zn (p < .05) and negative correlations with MDA, NO and Fe (p < .05) among neonates of the 3 studied groups. In conclusion, different photo therapies have an impact on oxidant/antioxidant balance and are associated with increased oxidative stress markers with the LED phototherapy being the safest.

Transient amelioration of the sensitization of cocaine-induced behaviors in rats by the induction of tolerance.

Intermittent administration of cocaine produced a progressive increase in the stereotypy response of rats to a challenge dose of cocaine (7.5 mg/kg, i.p.). Continuous infusion of cocaine (80 mg/kg per day) via osmotic pumps for 7 days into the sensitized rats produced tolerance to the behavioral responses to the challenge dose of cocaine 1 day after the removal of the pumps. Therefore, tolerance can mask the expression of behavioral sensitization in rats. However, by 10 days after the removal of the pumps, the behavioral tolerance was reversed and the rats again displayed a sensitized response to cocaine. Therefore, the tolerance to cocaine was temporary while the underlying sensitization persisted. The development of tolerance did not alter the underlying sensitization demonstrating that these represent independent phenomena. The relationship between sensitization and tolerance observed in these studies may provide a model relevant to the progress in humans of addiction to psychomotor stimulants.