RESUMO
Purpose@#Preterm infants are known to be at a risk of neurodevelopmental delay; however, limited data are available on the outcomes of moderate-to-late preterm (MLPT) infants (born at 32 to 36 weeks’ gestation). The Korean Developmental Screening Test (K-DST) for infants and children is a recently designed screening test for Korean infants and children. The current study aimed to evaluate the neurodevelopmental outcomes of MLPT infants and investigate the risk factors associated with neurodevelopmental delay. @*Methods@#A total of 119 MLPT infants admitted to a neonatal intensive care unit (NICU) of a tertiary hospital in Korea were enrolled. The infants were assessed during two follow-up periods (first: 16 to 24 months of corrected age; second: 24 to 41 months of corrected age). The perinatal factors in the NICU that were associated with delayed development were analyzed. @*Results@#In all sections of the K-DST, the proportion of infants with developmental delay was higher in the second period (5.6% to 9.3%) than in the first period (0.9% to 5.4%). A total of 10% to 17% of the infants presented with persistent delay throughout the two periods based on five sections of the K-DST. Male sex, oxygen therapy duration, and younger maternal age were the risk factors affecting at least one section during the second period. @*Conclusion@#MLPT infants showed greater developmental delay than the general infant population. Considering that early intervention is important for good longterm outcomes, close observation of male MLPT infants and MLPT infants who received oxygen therapy is warranted.
RESUMO
Purpose@#Preterm infants are known to be at a risk of neurodevelopmental delay; however, limited data are available on the outcomes of moderate-to-late preterm (MLPT) infants (born at 32 to 36 weeks’ gestation). The Korean Developmental Screening Test (K-DST) for infants and children is a recently designed screening test for Korean infants and children. The current study aimed to evaluate the neurodevelopmental outcomes of MLPT infants and investigate the risk factors associated with neurodevelopmental delay. @*Methods@#A total of 119 MLPT infants admitted to a neonatal intensive care unit (NICU) of a tertiary hospital in Korea were enrolled. The infants were assessed during two follow-up periods (first: 16 to 24 months of corrected age; second: 24 to 41 months of corrected age). The perinatal factors in the NICU that were associated with delayed development were analyzed. @*Results@#In all sections of the K-DST, the proportion of infants with developmental delay was higher in the second period (5.6% to 9.3%) than in the first period (0.9% to 5.4%). A total of 10% to 17% of the infants presented with persistent delay throughout the two periods based on five sections of the K-DST. Male sex, oxygen therapy duration, and younger maternal age were the risk factors affecting at least one section during the second period. @*Conclusion@#MLPT infants showed greater developmental delay than the general infant population. Considering that early intervention is important for good longterm outcomes, close observation of male MLPT infants and MLPT infants who received oxygen therapy is warranted.
RESUMO
Lysolipids such as LPA, S1P and SPC have diverse biological activities including cell proliferation, differentiation, and migration. We investigated signaling pathways of LPA-induced contraction in feline esophageal smooth muscle cells. We used freshly isolated smooth muscle cells and permeabilized cells from cat esophagus to measure the length of cells. Maximal contraction occurred at 10(-6) M and the response peaked at 30s. To identify LPA receptor subtypes in cells, western blot analysis was performed with antibodies to LPA receptor subtypes. LPA1 and LPA3 receptor were detected at 50 kDa and 44 kDa. LPA-induced contraction was almost completely blocked by LPA receptor (1/3) antagonist KI16425. Pertussis toxin (PTX) inhibited the contraction induced by LPA, suggesting that the contraction is mediated by a PTX-sensitive G protein. Phospholipase C (PLC) inhibitors U73122 and neomycin, and protein kinase C (PKC) inhibitor GF109203X also reduced the contraction. The PKC-mediated contraction may be isozyme-specific since only PKCepsilon antibody inhibited the contraction. MEK inhibitor PD98059 and JNK inhibitor SP600125 blocked the contraction. However, there is no synergistic effect of PKC and MAPK on the LPA-induced contraction. In addition, RhoA inhibitor C3 exoenzyme and ROCK inhibitor Y27632 significantly, but not completely, reduced the contraction. The present study demonstrated that LPA-induced contraction seems to be mediated by LPA receptors (1/3), coupled to PTX-sensitive G protein, resulting in activation of PLC, PKC-epsilon pathway, which subsequently mediates activation of ERK and JNK. The data also suggest that RhoA/ROCK are involved in the LPA-induced contraction.