RELATIONSHIP BETWEEN INSULIN-LIKE GROWTH FACTOR TYPE 1 AND INTRAUTERINE GROWTH.

Insulin-like growth factor 1 (IGF-1) is a regulator of intrauterine growth, and circulating concentrations are reduced in intrauterine growth-restricted fetuses. The aim of our study was to investigate the relationship between IGF-1 levels in newborns and intrauterine growth, expressed as birth weight (BW). The research was designed as a cross-sectional study. The study included 71 premature newborns, gestational age (GA) ≤33 weeks. Quantitative determination of IGF-1 was performed in the 33rd post-menstrual week (pmw) to make the measurements more comparable. We used an enzyme-bound immunosorbent test for quantitative determination of IGF-1. Our results showed the mean IGF-1 level in premature newborns in 33rd pmw to be 23.1±4.56 (range 15.44-39.75) µg/L. There was no difference in IGF-1 values between male (23.1±4.98 µg/L) and female (23.1±4.87 µg/L) newborns. There was no significant difference in the average IGF-1 levels between male and female newborns with BW <50th and BW >50th percentile for GA either (p>0.50). Only BW <33rd percentile newborns had a statistically significantly lower IGF-1 level compared to newborns with greater BW. Based on our results, it is concluded that serum IGF-1 level reflects intrauterine growth only in BW <33rd percentile newborns. This fact could be used for further therapeutic purposes.

PRO-OXIDANTS AND ANTIOXIDANTS IN RETINOPATHY OF PREMATURITY.

- Premature infants are susceptible to oxidative stress that causes neonatal disease such as retinopathy of prematurity (ROP). Oxidative stress is an imbalance between the production of pro-oxidants and the ability of the body to detoxify their harmful effects by antioxidants. The proliferative phase 2 ROP occurs at around 33rd postmenstrual week (pmw). The purpose of our study was to evaluate the pro-oxidant/antioxidant status in preterm infants at 33rd pmw. The study included 59 premature infants. ROP was classified according to the International Classification of Retinopathy of Prematurity. Total oxidative status (TOS), total antioxidant status (TAS), malondialdehyde (MDA) and paraoxonase 1 (PON1) activity were determined spectrophotometrically. The values of the pro-oxidants TOS and MDA were significantly higher in infants with ROP as compared to infants without ROP (p<0.05 both). There were no significant differences in the values of TAS and PON1 between the infants with and without ROP. According to study results, TOS and MDA are good markers of oxidative stress, whereas TAS and PON1 activity are unreliable in assessing antioxidant protection.

On the asymptotic behavior of the Douglas-Rachford and proximal-point algorithms for convex optimization.

Banjac et al. (J Optim Theory Appl 183(2):490-519, 2019) recently showed that the Douglas-Rachford algorithm provides certificates of infeasibility for a class of convex optimization problems. In particular, they showed that the difference between consecutive iterates generated by the algorithm converges to certificates of primal and dual strong infeasibility. Their result was shown in a finite-dimensional Euclidean setting and for a particular structure of the constraint set. In this paper, we extend the result to real Hilbert spaces and a general nonempty closed convex set. Moreover, we show that the proximal-point algorithm applied to the set of optimality conditions of the problem generates similar infeasibility certificates.

Tachycardia in a newborn with enterovirus infection.

Enterovirus infections are common in the neonatal period. Newborns are at a higher risk of severe disease including meningoencephalitis, sepsis syndrome, cardiovascular collapse, or hepatitis. The mechanism of heart failure in patients with enterovirus infection remains unknown. Early diagnosis may help clinicians predict complications in those infants initially presenting with severe disease. An 11-day-old male newborn was admitted to our neonatal intensive care unit because of tachycardia and crises of cyanosis. His elder brother had febrile illness. The newborn was cyanotic, in respiratory distress, with tachycardia, low blood pressure and prolonged capillary refilling time. Limb pulse oximeter was around 85%. During the first day of hospitalization, the newborn had one febrile episode. Laboratory data: elevated transaminases, markers of inflammation negative, all bacterial cultures negative. Enterovirus RNA was detected in blood sample. Other blood findings were without significant abnormalities. Electrocardiogram showed tachycardia, with narrow QRS complexes (atrial tachycardia) and heart rate up to 280/min. In order to convert the rhythm, the patient was administered adenosine and amiodarone. In the further course of hospitalization, the patient was in good general condition, eucardiac and eupneic. Newborns with tachycardia and a family history of febrile illness should be suspected to have enterovirus infection. Enterovirus infection is a highly contagious and potentially life-threatening infection if not detected early. The use of sensitive molecular-based amplification methods offers potential benefits for early diagnosis and timely treatment.