EEG, brain maturation, and the development of retinopathy of prematurity.

OBJECTIVES: The factors that influence the central nervous system (CNS) development can affect either the retina or the brain cortex. Immaturity of the brain cortex reflects immaturity of the retina and vice versa. The immature retina is more vulnerable than the mature retina, and is therefore more likely to develop retinopathy of prematurity (ROP). The aim of this study was to compare electroencephalographic brain maturity with ROP severity. METHODS: Twenty-one prematurely born infants were divided into two groups according to the severity of ROP. The first group included 12 infants with ROP stage 3 or more and the second group included nine infants with ROP stage 2 or less. We have proposed an index of CNS maturity (M) as a percentage of interburst interval elongation compared with the norm using video-electroencephalography (vEEG). RESULTS: The median M value was 1.07 (range = 0.43-4.44) for infants with severe ROP and -0.1 (range = -1.0 to 1.45) for infants with mild or no ROP (p = 0.000948). CONCLUSIONS: The study revealed that CNS maturation delay expressed as M value was higher among infants with severe ROP than among infants with mild or no ROP. EEG examination in prematurely born infants may prove to be a useful tool for predicting ROP development.

The role of hemoglobin variant replacement in retinopathy of prematurity.

OBJECTIVE: To conduct tests of relationships between different factors that could influence the course of retinopathy of prematurity (ROP) and ROP, particularly the role of hemoglobin variant replacement in adult blood transfusions. METHODS: A retrospective, observational study of 83 infants born between 23 and 34 wks gestation was conducted. RESULTS: The infants without ROP, with 1 and 2 stage of ROP and with ≥ 3 stage of ROP received Q 28 (12-134); 51 (14-149); 156 (38-244) ml/kg of transfused blood, respectively, and the factor Qt was 1,545 (560-10,045); 3,093 (614-13,419); 11,907 (1,288-20,638) (ml/kg)·day, respectively. For the same groups MCV(35) (mean cell volume at the arbitrary time of the 35(th) wk post-conception) was 92.3 (82.9-110.5); 91.0 (79.3-101.4); 87.1 (80.2-94.8) fl, respectively, and factor P(MCV)/t was 99.5 (89.2-108.8); 96.3 (84.6-106.3); 90.7 (85.3-96.5) fl, respectively. There is high influence on the stage of ROP of the amount of transfused blood and MCV, both with or without the time factor. The statistical differences between P(MCV)/t were more significant than the differences between MCV(35), for different stages of ROP. CONCLUSIONS: The influence of the time factor on the statistical differences of MCV but not on the amount of transfused adult blood suggests that HbF - HbA replacement may play a role in ROP development.

Interactions of dihydrochloride fluphenazine with DPPC liposomes: ATR-IR and 31P NMR studies.

The influence of dihydrochloride fluphenazine (FPh) on the dipalmitoylphosphatidylcholine (DPPC) bilayer structure was investigated using ATR-IR and (31)P NMR methods. The ATR-IR results indicate an increase in conformational disorder in the hydrophobic part compared with pure DPPC liposomes and a decrease in temperature of the chain-melting phase transition in FPh/DPPC liposomes. These effects depended on the concentration of the drug in the DPPC bilayer. The dihydrochloride fluphenazine molecules form H-bonds with the proton-acceptor carbonyl groups of DPPC molecules. At a higher concentration of the drug, the lipid bilayer structure is destroyed, and an isotropic phase is observed using (31)P NMR spectroscopy. The interactions between FPh and the lipid bilayer have a crucial role in MDR (multidrug-resistant) activity of this drug. These results improve one possible strategy of cancer chemoprevention with FPh accompanied by fluidization and destabilization of the model lipid bilayer structure.