No abstract

Increased urine S100B protein levels in intrauterine growth retardation newborns in the first week after birth suggest the presence of brain damage reasonably because of intrauterine hypoxia. Longitudinal S100B protein measurements soon after birth are a useful tool to identify which intrauterine growth retardation infants are at risk of possible neurologic sequelae.

Prematurity is an important cause of perinatal death, and no reliable biochemical/biophysical markers exist to identify newborns with an increased mortality risk. We aimed to use S100B concentrations in urine as an early indicator of risk of neonatal death. We did a cross-sectional study using urine obtained from 165 preterm newborns, of whom 11 suffered neonatal death within the first week, 121 displayed no overt neurologic syndrome, and 33 suffered neonatal hypoxia and intraventricular hemorrhage (IVH) but not ominous outcome. Urine S100B concentrations were determined at four time-points and corrected for gestational age by conversion to multiples of median (MoM) of healthy controls of the same gestational age. Ultrasound imaging was assessed within the first 72 h from birth. In infants that died within the first week, S100B levels in urine were already higher than controls at first urination and increased progressively between the 24 and 96-h time-points. Multiple logistic regression analysis showed a significant correlation between urine S100B protein concentrations and the occurrence of neonatal death. An S100B concentration cut-off of 12.93 MoM at first urination had a sensitivity of 100% and a specificity of 97.8% for predicting an ominous outcome. The positive predictive value was 78.6%, the negative predictive value was 100%. Measurement of urine S100B protein levels in preterm newborns could be useful to identify newborns at higher risk of neonatal death. Prematurity constitutes the main cause leading to perinatal death and about 10 -15% of high-risk newborns might have an ominous outcome (1,2). The possibility of early identification of infants at higher risk of death is to date limited, inasmuch as clinical, laboratory and standard monitoring procedures may be of no avail. There is thus a constant need for practical and sensitive markers able to identify patients at higher risk as early as possible, to take immediate preventive or therapeutic measures. The inclusion of such a marker in evidence-based guidelines is eagerly awaited; however, at present no effective biochemical or biophysical tools exist to predict newborns at higher risk of perinatal death (1-4).The presence in blood of elevated concentrations of a brain constituent such as S100B protein has been described as prognostic of death in adults, and it has been suggested that measurement of this protein be included among peri-mortem procedures (5). S100B is an acidic calcium-binding protein of the EF-hand family (6) that is highly concentrated in the nervous system; it has a half-life of about 1 h and is mainly eliminated in urine (7). In this respect, raised urine S100B concentrations are a consolidated marker of brain damage in infants (8 -10) and in preterm newborns with IVH (11), whereas increased amniotic fluid S100B concentrations are a marker of fetal death (12). Because urine is a clinically accessible fluid for the measurement of S100B when monitoring newborns at high risk, we aimed to evaluate whether

BackgroundPerinatal asphyxia (PA) is a leading cause of mortality and morbidity in newborns: its prognosis depends both on the severity of the asphyxia and on the immediate resuscitation to restore oxygen supply and blood circulation. Therefore, we investigated whether measurement of S100B, a consolidated marker of brain injury, in salivary fluid of PA newborns may constitute a useful tool for the early detection of asphyxia-related brain injury.MethodsWe conducted a cross-sectional study in 292 full-term newborns admitted to our NICUs, of whom 48 suffered PA and 244 healthy controls admitted at our NICUs. Saliva S100B levels measurement longitudinally after birth; routine laboratory variables, neurological patterns, cerebral ultrasound and, magnetic resonance imaging were performed. The primary end-point was the presence of neurological abnormalities at 12-months after birth.ResultsS100B salivary levels were significantly (P<0.001) higher in newborns with PA than in normal infants. When asphyxiated infants were subdivided according to a good (Group A; n = 15) or poor (Group B; n = 33) neurological outcome at 12-months, S100B was significantly higher at all monitoring time-points in Group B than in Group A or controls (P<0.001, for all). A cut-off >3.25 MoM S100B achieved a sensitivity of 100% (CI5-95%: 89.3%-100%) and a specificity of 100% (CI5-95%: 98.6%-100%) as a single marker for predicting the occurrence of abnormal neurological outcome (area under the ROC curve: 1.000; CI5-95%: 0.987-1.0).ConclusionsS100B protein measurement in saliva, soon after birth, is a useful tool to identify which asphyxiated infants are at risk of neurological sequelae.

The aim of this preliminary study was to assess the possible presence of cholesterol oxidation products in 2 i.v. lipidic emulsions with different fatty acid compositions (long-chain triglyceride, medium-chain triglyceride-long-chain triglyceride). Because these emulsions are currently used in neonatal parenteral nutrition, their direct venous introduction might be potentially dangerous because of the possible atherogenic role of cholesterol oxidation products. The emulsions were analyzed when bottles were opened (ie, under normal condition of administration) and after a 12-hour direct experimental exposure to air and high (90%) oxygen concentrations. 7-Ketocholesterol and 5alpha-epoxycholesterol were chosen as markers of cholesterol oxidation and detected by gas chromatography-mass spectrometry of their trimethylsilyl ethers. The detected amounts were always very low and in some cases below the detection limit of the analytical method for the 2 cholesterol oxidation products (COPs; 0.1 and 0.3 microg/g of extracted lipids). Immediately after opening the bottles, their concentrations were lower in the emulsions containing the higher amounts of polyunsaturated fatty acids. Experimental hyperoxic exposure generally determined only a mild increase in the content of cholesterol oxidation biomarker, and after exposure to oxygen, the amounts of COPs were slightly higher than after exposure to air. The results of the present study are undoubtedly reassuring for the safety of neonates, although caution is always required when drawing conclusions from in vitro data.