Possible antiapoptotic and neuroprotective effects of magnesium sulphate on retina in a preterm hypoxic-ischemic rat model

Background/aim: The effects of systemic magnesium sulfate (MgSO4) on retina in preterm hypoxic-ischemic (HI) rat model are not known. Our aim was to investigate the effects of MgSO4 on retinal ganglion cell (RGC) count, retinal ganglion cell (RGC) apoptotic index, retinal vascular endothelial growth factor receptor-2 (VEGFR-2), and glial fibrillary acidic protein (GFAP) expressions in preterm HI rat model. Materials and methods: Fifteen, postnatal day (PND) 7 rat pups were divided into 3 groups: 1. Sham-operated group, 2. HI group, and 3. MgSO4-treated HI group. The second and third groups underwent ischemia followed by exposure to hypoxia for 2 h (Vannucci model). The first and second groups received intraperitoneal saline and the third group received intraperitoneal MgSO4. On PND 10, eyes of the pups were evaluated for RGC count, apoptotic index, VEGFR-2, and GFAP expressions. Results: In both HI and MgSO4-treated HI group, the mean total RGC counts were found to be significantly decreased. However, the mean total RGC count in the MgSO4-treated HI group was significantly higher than that of the HI group. The mean apoptotic index was found to be significantly increased in the HI group. Retinal VEGFR-2 and GFAP expressions were found to be significantly higher in the HI group. Conclusions: Magnesium sulfate preconditioning and treatment in preterm HI rat model might diminish apoptosis, relatively preserve RGCs, and reduce retinal VEGFR-2 and GFAP expressions.

Birth Weight Reference Percentiles by Gestational Age for Turkish Twin Neonates.

AIMS: In clinical practice, birth weight reference percentiles for singletons are used to evaluate twin births. The utilization of singleton reference percentiles for twins is not appropriate as they experience different growth trajectories. However, Turkey still lacks such references. Our aim was to create gestational age-specific birth weight references for female and male Turkish twins. MATERIALS AND METHODS: This is a hospital-based, multi-centered, retrospective study. In total, 2544 live-born twins between 2010 and 2019 were included in the study. Gestational age, birth weight, mode of delivery, gender, birth order, chorionicity, maternal age, pregnancy resulting from assisted reproduction techniques, APGAR (Appearance, Pulse, Grimace, Activity, and Respiration) score at 5 minutes, admission to the neonatal intensive care unit (NICU), length of stay in NICU, and death during the NICU stay were recorded. RESULTS: Smoothed reference curves for birth weight by gestational age and separate tables for female and male twin neonates for the 3rd, 10th, 50th, 90th, and 97th percentiles from 26 to 39 weeks of gestational age were constructed. Overall neonatal and infant mortality rates during NICU stay in our twin cohort were 12/1000 and 16/1000, respectively. CONCLUSION: Twin-specific birth weight nomograms could be helpful as a reference for clinicians to identify high-risk neonates and fetuses who need specialized care. However, further studies with larger series are urgently needed for validation and use of these nomograms in clinical practice.

Does being born small-for-gestational-age affect cerebellar size in neonates?

OBJECTIVE: To investigate how cerebellar vermis height (CVH) and transverse cerebellar diameter (TCD) measurements are affected in SGA neonates. METHODS: A total of 176 [88 SGA and 88 appropriate for gestational age (AGA)] neonates between 26 and 42 weeks of gestation were included. Midsagittal plane through the anterior fontanel and coronal plane through the left mastoid fontanel were used to measure CVH and TCD, respectively. CVH and TCD values were considered normal when they were ≥ 10th percentile, according to nomograms of AGA neonates. RESULTS: Thirty-six asymmetric SGA neonates, 52 symmetric SGA neonates and their 88 gestational age-matched AGA controls were studied. The percentages of neonates with normal CVH and TCD in the symmetric SGA sub-group were significantly lower than those in the AGA and asymmetric SGA sub-groups. The percentages with normal CVH and TCD in the asymmetric SGA sub-group were also found to be low when compared with the AGA sub-group. CONCLUSION: Growth and development of cerebellum may be less spared in SGA neonates. Further studies with larger series are needed in order to evaluate how being born SGA (symmetric and asymmetric) affects cerebellar size and also to see how these findings influence the neurocognitive outcomes of these infants at long-term follow-up.

Effect of laser photocoagulation on plasma levels of VEGF-A, VEGFR-2, and Tie2 in infants with retinopathy of prematurity.

PURPOSE: To report the baseline plasma levels of vascular endothelial growth factor-A (VEGF-A), soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) and soluble Tie2 in infants with treatment-requiring retinopathy of prematurity (ROP) and to investigate the effect of laser treatment on the plasma levels. METHODS: Blood samples were collected from infants with prethreshold type 1 ROP before, 1 day after, and 1 week after confluent laser photocoagulation. Enzyme-linked immunosorbent assay procedure was used to determine plasma VEGF-A, sVEGFR-2, and sTie2 levels. RESULTS: A total of 48 eyes of 30 infants were included. The mean postconceptional age at which laser photocoagulation was performed was 37.5 ± 2.9 weeks. The mean number of laser spots applied to each eye was 1,480 ± 420. Regression of active retinopathy occurred within 1 week of treatment in all cases. Baseline plasma VEGF-A, sVEGFR-2, and sTie2 levels did not differ between unilateral and bilateral and also zone I and zone II disease. A significantly progressive decrease was observed in plasma VEGF-A, sVEGFR-2, and sTie2 levels at 1 day and 1 week after laser photocoagulation. CONCLUSIONS: Plasma levels of VEGF-A, sVEGFR-2, and sTie2 decreased significantly in our patients after laser treatment; however, because of the variability in the measurements, further studies evaluating the clinical value of these angiogenic factors in patients with treatment-requiring ROP are necessary.