Long-term Effects of Indirect Hyperbilirubinemia on Auditory and Neurological Functions in Term Newborns.

OBJECTIVE: The aim of this study was to investigate the long-term effects of hyperbilirubinemia on neurological and hearing function in otherwise healthy term newborns with neonatal indirect hyperbilirubinemia. METHOD: This study was performed prospectively in 41 term newborns hospitalized for indirect hyperbilirubinemia. Patients with no signs of hemolysis were categorized in 3 groups based on stabil levels as sTB <20 mg/dl, 20-24.9 mg/dl, and =>25 mg/dl. Patients with total bilirubin level =>20 mg/dl and hemolytic disease were classified as the fourth group. The relationship between maximum sTB level, duration of exposure to sTB levels >20 mg/dl and etiology of jaundice with neurological and auditory functions was investigated. Detailed neurological examination, Denver II developmental screening test and hearing tests (otoacoustic emissions, OAE and auditory brainstem responses, ABR) were performed to all patients between 18-24 months of age. RESULTS: Neurodevelopmental disorder was found in 5 (12.2%) patients. Hemolytic disease was detected in two of these patients. Hearing loss was found in 4 (9.8%) of the patients. Two of these patients had auditory neuropathy spectrum disorder and the other two had cochlear hearing loss. The sTB levels of all these patients were above 25 mg/dl. No neurological disorder or hearing loss was found in the patients who had stabil of <25 mg/dl. Exposure time to sTB levels above 20 mg/dl was significantly longer in patients with neurological dysfunction and pathologic ABR results (p:0.007, p:0.007; p<0.05). CONCLUSION: This study demonstrates that kernicterus may develop in term newborns with severe hyperbilirubinemia (sTB>25 mg/dl) without any finding of significant hemolysis. Not only the bilirubin level but also the duration of exposure to high bilirubin levels may be effective in the development of bilirubin neurotoxicity. The high rate of hearing loss in our patients emphasizes the importance of screening for infants with severe hyperbilirubinemia using comprehensive auditory evaluation for early diagnosis of possible hearing loss.

The association of ghrelin, leptin, and insulin levels in umbilical cord blood with fetal anthropometric measurements and glucose levels at birth.

Objectives: To investigate the association of ghrelin, leptin, and insulin levels in the umbilical cord blood of the preterm and term infants with anthropometric measurements and glucose metabolism.Methods: Sixty-nine infants who were born between November 2004 and June 2005 were included in the study. Pregnancy ages, birth weights, heights, head circumferences, and Ponderal Indexes (PI) were identified. Ghrelin, leptin, insulin, and glucose levels in the umbilical cord blood were studied.Results: Eighteen infants out of 69 infants were preterm (34.6 ± 0.43 weeks), and 33 infants were term (38.7 ± 0.14 weeks). All preterm infant weights were appropriate for gestational age (AGA); 33 of the term infants' weights were AGA and 18 were large for gestational age (LGA). Leptin, insulin, and glucose levels of term infants were significantly higher compared with the preterm infants (p < .0001, p < .001, and p < .0001, respectively); no significant difference was detected in the ghrelin levels between the two groups (p > .05). The leptin and insulin levels of the term LGA infants were higher compared with the term AGA and preterm AGA infants (p < .05, for all). No difference was detected between the three groups regarding serum ghrelin levels (p > .05). No difference was found in the glucose levels between term AGA and LGA infants (p > .05); however, the serum glucose levels of term AGA and LGA infants were higher compared with levels in preterm AGA infants (p < .05, for both). A positive correlation was demonstrated in all study groups between leptin and insulin with gestational age, body weight, height, head circumference, and PI. A positive correlation was found between serum leptin levels with gestational age and insulin levels in preterm infants, and between serum leptin levels and insulin and glucose levels in term infants. No association was found between ghrelin and anthropometric measurements, leptin, insulin, and glucose levels (p > .05, for all).Conclusions: The increase of leptin production with increased gestational age, and the strong association with anthropometric measurements supports the opinion that leptin behaves as a fetal growth factor. Leptin in intrauterine life is in close association with insulin and glucose metabolism. Although ghrelin was at measurable levels in preterms, no association with fetal growth and glucose metabolism could be demonstrated in preterm and term infants.

The Role of Umbilical Cord Blood Concentration of IGF-I, IGF-II, Leptin, Adiponectin, Ghrelin, Resistin, and Visfatin in Fetal Growth.

OBJECTIVE: Herein, we measured the concentration of insulinlike growth factor I (IGF-I), IGF-II, leptin, adiponectin, ghrelin, resistin, and visfatin in the umbilical cord blood of newborns categorized as "small for gestational age" (SGA), "appropriate for gestational age" (AGA), and "large for gestational age" (LGA). Our aim was to elucidate the link between the levels of these proteins and fetal growth. STUDY DESIGN: A total of 96 term infants were included and categorized into three weight categories. Their venous cord blood samples were collected to measure the levels of IGF-I, IGF-II, leptin, adiponectin, ghrelin, resistin, and visfatin. RESULTS: IGF-I, visfatin, and leptin levels showed significant differences among the groups. Pairwise comparisons showed that adiponectin (p = 0.023), resistin (p = 0.025), and ghrelin (p = 0.005) levels were significantly lower in the SGA group than in the LGA group. Correlation analyses showed a strong association of IGF-1, IGF-II, and leptin levels with birth weight (r = 0.644, p < 0.001; r = 0.441, p < 0.001; and r = 0.404, p < 0.001, respectively). CONCLUSION: SGA newborns showed a significantly higher visfatin concentration and lower ghrelin, leptin, resistin, and adiponectin levels than the AGA and LGA newborns did.

Does intratympanic xylitol administration have ototoxic effects in a mouse ear model?

OBJECTIVE: To research the ototoxicity of xylitol after intratympanic injection in mice ear model. METHODS: 24 female mice Balb/c mice (48 ears) included in the study. The mice were divided into 4 groups as 6 mice were found (12 ears) in each group. Solutions of 0.9% NaCl solution (Group A), 155 mg/ml (Group B), 310 mg/ml (Group C) and 620 mg/ml (Group D) xylitol, were applied into the middle ear cavity. Microscopic ear examination and auditory brainstem response test were done for each mouse before application of xylitol and on the 1st, 3rd and 10th day of injection. RESULTS: There are some statistically significant alterations found in the threshold values at 8000, 12000, 16000, 24000 Hz frequencies when each group were compared in itself on day 0, 1,3 and 10, which were independent from the increasing dosage. CONCLUSION: According to our findings intratympanic xylitol injection does not have any ototoxic effect in the inner ear. To evaluate the effects of xylitol more clinical studies are need to carried out.

Ethical dimensions of periviability.

The birth of neonates at the limits of viability, or periviability, poses numerous challenges to health care providers and to systems of care, and the care of these pregnancies and neonates is fraught with ethical controversies. This statement summarizes the ethical principles involved in the care of periviable pregnancies and neonates, and provides expert clinical opinion about the numerous challenges posed by this problem around the world. Topics addressed include a summary of the published experience, an ethical framework, translating neonatal outcome data to the obstetric arena, management as a trial of intervention, referral to tertiary centers, neonatal resuscitation, cesarean delivery for fetal indication, and limits on life-sustaining neonatal treatment.

Plasma and urinary endothelin-1 concentrations in asphyxiated newborns [corrected].

The aim of this study was to determine if there is any correlation between the hypoxia induced deterioration of renal functions and urinary excretions of endothelin (ET). Therefore using a sensitive and specific radioimmunoassay, we have investigated plasma ET-1 concentrations and urine ET-1 excretions in healthy and asphyxiated newborns. Sixteen newborns (10 boys, 6 girls) with perinatal asphyxia or hypoxia of variable seriousness which were followed at Newborn Intensive Care Unit in Eskisehir Osmangazi University Faculty of Medicine were enrolled. Simultaneously, gestation and weight matched 10 newborns (6 boys, 4 girls) with no asphyxia (first minute Apgar score >7) were enrolled as controls. Plasma ET-1 concentrations of the asphyxiated infants (61.8+/-79.3 pg/ml, between 23.4-125.2 pg/ml) were higher than in the control group (29.3+/-22.1 pg/ml, between 12.3 and 50.8 pg/ml, p<0.05). However creatinine clearance values were not different between the two groups (p>0.05), mean fractional excretion of sodium levels (FeNa%) were higher in the study group than the controls (p<0.01). Urinary ET-1 concentrations in the asphyxiated infants were 144.6+/-63.4 pg/ml versus 70.1+/-27.7 pg/ml in the control group (p<0.001). The ET clearance were more elevated in the asphyxiated newborns than in the healthy infants (p<0.05). Urinary ET-1/Cr ratio in the hypoxic infants were significantly elevated in the first day of life when compared with those of healthy infants (p<0.05). Total ET excretion was negatively correlated with FeNa (%) (r=-0.603, p<0.05). Plasma ET-1 concentrations of the asphyxiated infants reduced at 48 hours of age (p<0.001). Fifth minute Apgar score was negatively correlated with urinary ET-1 levels (r=-0.615, p<0.01), urinary Na excretion (r=-0.583, p<0.01), FeNa (%) (r=-0.597, p<0.01) and total ET excretion (r=-0.560, p<0.01) and positively correlated with ET clearance (r=0.559, p<0.05). Urinary ET-1 levels were negatively correlated with umbilical artery BE levels (r=-0.612, p<0.05). To our study, elevated urinary ET-1 levels were observed during perinatal asphyxia and urinary ET-1 levels were negatively correlated with 5th minute Apgar score and cord blood base excess levels. For this reason urinary ET-1 levels could be a marker of perinatal asphyxia as cord blood ET-1 levels. With investigations showing renal production is independent from plasma and increased urinary ET-1/Cr levels in newborn with perinatal asphyxia and also negative correlation between the total ET excretion and FeNa, urinary ET-1 levels could be served as a useful marker to detecting also impaired renal functions in infants with perinatal asphyxia.

Longitudinal behaviour of neural response telemetry (NRT) data and clinical implications.

Neural response telemetry (NRT) data from 63 subjects equipped with the Nucleus CI24M Cochlear Implant System generally exhibited little change over up to 4 years. Larger changes, when they occurred, were seen only within the first 15 months postoperatively, and these changes diminished over time. Intraoperative NRT data were generally stable enough to be used for assisting in the initial speech processor fitting sessions. It was not possible to predict changes in the subjective map threshold and comfortable loudness levels (T and C levels, respectively) based on observed changes in the NRT data. The long-term stability of the neural response amplitude and the neural response threshold, however, implies that NRT may be useful as a routine diagnostic tool to detect changes to the neural periphery over time.