[Early and late complications of hyperglycemic extremely low birth-weight infants]. / Az extrém alacsony születési súlyú koraszülöttek hyperglykaemiájának korai és késoi szövodményei.

Introduction: During recent decades, the perinatal mortality of extremely low-birth weight infants has decreased. An important task is to recognize complications of prematurity. Aim: We made an attempt to explore the relationship between complications of prematurity and neonatal hyperglycemia. Method: From 1 January 2014 to 31 December 2017, 188 infants with birth weight below 1000 g were admitted. For each infant, the frequencies of hyperglycemia (blood glucose >8.5 mmol/l), retinopathy of prematurity, intraventricular hemorrhage, and bronchopulmonary dysplasia were determined. Animal studies were performed in Sprague Dawley rats. Hyperglycemia was achieved by intraperitoneal injection of streptozotocin (100 mg/kg). On the 7th day of life, aorta sections were prepared and stained with hematoxylin eosin. Wall thickness was measured using QCapture Pro 7 image analysis software. Results: The mean ± SD gestational age and birth weight were 27.1 ± 2.2 weeks and 814.9 ± 151.9 g; 33 infants (17.5%) died. Hyperglycemia was confirmed in 62 cases (32.9%), and insulin treatment was given to 43 infants (22.8%). The gestational age and birth weight of the hyperglycemic infants were significantly lower (p<0.001), the incidence of severe retinopathy (p = 0.012) and the mortality of insulin-treated patients were higher (p = 0.02) than in normoglycemic infants. Among survivors (n = 155), we found by logistic regression analysis that hyperglycemia was a risk factor for severe retinopathy (p<0.001). In the rat model, neonatal hyperglycemia caused significant thickening of the aortic wall. Conclusion: Our studies indicate that hyperglycemia is common in extremely low birth-weight infants. Monitoring of these infants for retinopathy of prematurity, kidney dysfunction, and hypertension is recommended. Orv Hetil. 2019; 160(32): 1270-1278.

PACAP Is Protective in a Rat Model of Retinopathy of Prematurity.

The oxygen-induced retinopathy (OIR) is a well-established rodent model of retinopathy of prematurity (ROP), which is one of the most common causes of childhood visual impairment affecting preterm babies. Pituitary adenylate cyclase-activating polypeptide (PACAP) is known to have neuroprotective effects. Several studies have revealed the presence of PACAP and its receptors in the retina and reported its protective effects in ischemic and diabetic retinopathy. In this study, we investigated whether PACAP administration can influence the vascular changes in the rat OIR model. OIR was generated by placing the animals in daily alternating 10/50 oxygen concentrations from postnatal day (PD) 0 to PD14 then returned them to room air. Meanwhile, animals received PACAP or saline intraperitoneally or intravitreally from PD1 to PD8 or on PD11, PD14, and PD17, respectively. On PD19 ± 1, the retinas were isolated and the vessels were visualized by isolectin staining. The percentage of avascular to whole retinal areas and the number of branching points were measured. Change in cytokine expression was also determined. Intravitreal treatment with PACAP remarkably reduced the extent of avascular area compared to the non- and saline-treated OIR groups. Intraperitoneal PACAP injection did not influence the vascular extent. Retinal images of room-air controls did not show vascular alterations. No changes in the number of vessel branching were observed after treatments. Alterations in cytokine profile after local PACAP injection further supported the protective role of the peptide. This is the first study to examine the effects of PACAP in ROP. Although the exact mechanism is still not revealed, the present results show that PACAP treatment can ameliorate the vascular changes in the animal model of ROP.

Perinatal positive and negative influences on the early neurobehavioral reflex and motor development.

Early life events are critical in the development of the central nervous system. Injuries in this period can cause severe damage with permanent disabilities. The early changes following a perinatal lesion have prognostic significance. The nervous system in young age has a potential for plasticity and regeneration, which can prevent the negative effects of neuronal damage, and the most important objective of rehabilitation is to enhance this inner potential of the developing brain. Experimental examination of the environmental factors affecting this regeneration and remodeling process is very important. Endogenous factors, such as neurotrophic factors, which play a role in neurogenesis, migration, and differentiation of neurons, and development of neuronal circuits, are also in the center of interest. Most studies concerning the effect of positive or negative perinatal treatments focus mainly on long-term effects, and most examinations are carried out on adult animals following perinatal injuries. Less data are available on short-term effects and early neurobehavioral changes. In the past several years, we have shown how different (positive or negative) perinatal events affect the early neuronal development. Applying different tests widely used for behavioral testing, we have established a standardized testing method. This includes measuring parameters of somatic growth and facial development, appearance of basic neurological reflexes and also reflex performance, more complex motor coordination tests, and open-field and novelty-seeking tests. In the present chapter, we summarize data on early neurobehavioral development of newborn rats subjected to negative (perinatal asphyxia, hypoxia, excitotoxic injury, stress) and positive (enriched environment, neurotrophic factor treatment) stimuli during early postnatal life.