Methods: For the optimisation and validation protocol, β-cells were plated onto 35 mm plastic petri dishes and maintained in RPMI-1640 media supplemented with 10 mM glucose, 10% FCS and 25 mM of N-2-hydroxyethylpiperazine-N-ethanesulfonic acid (HEPES). The treatment effects of 10 mM glucose and 30 μM fluoxetine on KATP channels NPo of β-cells were assessed via cell-attached patch-clamp recordings. For hippocampus cell experiments, hippocampi were harvested from day 17 of maternal Lister-hooded rat foetus, and then transferred to a Ca2+ and Mg2+-free HEPES-buffered Hank's salt solution (HHSS). The dissociated cells were cultured and plated onto a 25 mm round cover glasses coated with poly-d-lysine (0.1 mg/mL) in a petri dish. The KATP channels NPo of hippocampus cells when perfused with 1 mM and 10 mM of KA were determined.
Results: NPo of β-cells showed significant decreasing patterns (P < 0.001) when treated with 10 mM glucose 0.048 (0.027) as well as 30 μM fluoxetine 0.190 (0.141) as compared to basal counterpart. In hippocampus cell experiment, a significant increase (P < 0.001) in mean NPo 2.148 (0.175) of neurons when applied with 1 mM of KA as compared to basal was observed.
Conclusion: The two concentrations of KA used in the study exerted contrasting effects toward the mean of NPo. It is hypothesised that KA at lower concentration (1 mM) opens more KATP channels, leading to hyperpolarisation of the neurons, which may prevent neuronal hyper excitability. No effect was shown in 10 mM KA treatment, suggesting that only lower than 10 mM KA produced significant changes in KATP channels. This implies further validation of KA concentration to be used in the future.
MATERIALS AND METHODS: This is an observational cohort study and retrospective case assessment, involved twins born at Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan between 2013 and 2018. DC twins with selective IUGR (sIUGR) were defined as the presence of a birth weight discordance of >25% and a smaller twin with a birth weight below the tenth percentile. PDA was diagnosed using echocardiography between postnatal day 3 and 7. Hs-PDA was defined as PDA plus increased pulmonary circulation, poor systemic perfusion, cardiomegaly, pulmonary edema, or hypotension requiring pharmacotherapeutic intervention.
RESULT: A total of 1187 twins were delivered during the study period, and 53 DC twins with selective IUGR were included in this study. DC twins with PDA have higher rate of preterm birth, lower gestational age of delivery, and lower mean birth weight of both twins compared with DC twins without PDA. In a comparison of the sIUGR twin with the appropriate for gestational age co-twin, both the incidences of PDA (28.30% vs. 7.55%, respectively; P = 0.003) and Hs-PDA (24.53% vs. 5.66%, respectively; P = 0.002) were higher in sIUGR fetuses than in the appropriate for gestational age co-twins. Small gestational age of delivery was the only variable to predict PDA and Hs-PDA [p = 0.002, Odds ratio = 0.57 (0.39-0.82), p = 0.009, Odds ratio = 0.71 (0.55-0.92), respectively].
CONCLUSION: An analysis of dichorionic twins with sIUGR indicated that IUGR increased the risk of PDA and hemodynamically significant PDA.