Free-radical-induced lipid peroxidation during the early neonatal period

The effect of gestational age on postnatal free-radical-mediated lipid peroxidation was studied in 19 term (gestational age 37–42 weeks) and 21 healthy preterm (gestational age 31–36 weeks) infants by measurement of expired ethane and pentane during the first 7 days of life. Ethane (11.9 versus 5.7 pmol/kg/min; p = 0.0001) and pentane (11.4 versus 7.5 pmol/kg/min; p = 0.01) were significantly higher in preterm than in term infants. Correlations were found between gestational age and ethane ( r = 0.60, p = 0.0001) for days 1–7 and pentane ( r = 0.54, p = 0.0003) for days 3–7; and between birth weight and ethane ( r = 0.58, p = 0.0001) and pentane (r = 0.55, p = 0.0003). These results indicate that during the postnatal period, immaturity is a major factor determining the rate of free-radial-mediated lipid peroxidation.     

临床和血流动力学稳定的早产儿生后第1周灌注指数变化

重症监护病房的新生儿,尤其是早产儿,生后第1周患病和死亡率较高,因而早期诊断新生儿各种并发症是新生儿医务工作者面临的巨大挑战。近年来,脉搏血氧仪(简称脉氧仪)已成为新生儿重症监护病房(NICU)的重要监测仪器之一。据报道,通过脉氧仪信号得出的灌注指数(perfusion index,PI)能反映外周血流的实时变化,并识别外周循环灌注不足的重症新生儿。近期已有报道新生儿PI值的相关文献,但关于早产儿的还较少。本研究旨在监测临床和血流动力学稳定早产儿生后第1周的PI值,从而为临床上推广应用提供依据。研究方法一、研究对象2007年11月至2008年4月入住意大利某儿童医院NICU的30例早产儿。入选     

临床和血流动力学稳定的早产儿生后第1周灌注指数变化

重症监护病房的新生儿,尤其是早产儿,生后第1周患病和死亡率较高,因而早期诊断新生儿各种并发症是新生儿医务工作者面临的巨大挑战。近年来,脉搏血氧仪（简称脉氧仪）已成为新生儿重症监护病房（NICU）的重要监测仪器之一。     

早产儿出生早期粪便钙卫蛋白水平变化及临床意义

目的：探讨早产儿生后早期粪便钙卫蛋白（fecal calprotectin,FC）水平及影响因素,寻找早产儿胃肠道损伤的早期诊断指标。方法：将38例胎龄为29～33周的早产儿按早产原因分为胎膜早破（premature rapture of membrane,PROM）组、自发性早产(spontaneous preterm birth,SPB)组及有医学指征早产(indicated preterm birth,IPB)组,收集出生后第1次胎便及生后第3天最后1次粪便（以下简称为第1次和第2次粪便）,用ELISA法测定FC水平。结果：38例早产儿第1次与第2次FC水平差异无统学计意义（P>0.05）。PROM组第1次FC水平明显高于IPB组（P0.05）。结论：胎膜早破及出生窒息促进早产儿胃肠道分泌FC,生后早期FC水平可反映早产儿早期胃肠道喂养状况,可作为评价早产儿生后早期消化道功能的指标。     

Nitric oxide production during the early neonatal period in small-for-gestational-age infants

In a study of endogenous nitric oxide production in growth-retarded, very preterm newborns (<32 wk GA), urinary NOx/creatinine ratio and plasma guanosine 3',5'-cyclic monophosphate levels were determined during the early neonatal period. Newborns were divided into three groups: appropriate-for-gestational-age (AGA, n = 19), moderately small-for-gestational-age (SGA, n = 13) and severely SGA (n = 6) infants. Severely SGA infants showed significant higher values of nitric oxide derivatives during the first 24 h of life compared with the other groups. CONCLUSION: An increased NO production is found in SGA infants during the first 24 h after birth. This may reflect an increased intrauterine nitric oxide production in the feto-placental circulation found in cases with intrauterine growth retardation,     

Adrenocortical steroids in small-for-gestational-age term infants during the early neonatal period

We evaluated adrenocortical steroid concentrations at birth and during postnatal adaptation (2 h until 7 days) in 10 vaginally delivered term small-for-gestational-age (SGA) infants and 12 term appropriate-for-gestational age infants. Plasma aldosterone, 11-deoxycorticosterone, corticosterone, progesterone, 17-hydroxyprogesterone, 11-deoxycortisol, cortisol, and cortisone were longitudinally measured by specific RIA after Sephadex LH-20 chromatography. Mean aldosterone was significantly higher in SGA than in appropriate-for-gestational-age infants (2 h to 7 days; p less than 0.001). In SGA infants, cortisone and cortisol levels were significantly lower in umbilical artery (p less than 0.05), and all glucocorticoid levels were significantly lower 12 h after birth (p less than 0.05). Thereafter (24 h to 7 days), only 11-deoxycortisol levels remained significantly lower in SGA; corticosterone and cortisol levels were even higher (p less than 0.05) in SGA 24 h after birth. The data suggest that SGA infants maintain high aldosterone levels throughout the 1st wk of life. Low cortisol and cortisone levels in umbilical artery as well as low glucocorticoid levels at 2 h and/or 12 h compared to term appropriate-for-gestational-age infants may reflect either a less stressful postnatal adaptation or, more likely, a reduced adrenocortical synthesis in term SGA infants.     

Endothelium-derived relaxing and contracting factors during the early neonatal period

Abstract The interaction and relative potency of nitric oxide, an endothelium-derived relaxing factor, and endothelin-1, an endothelium-derived contracting factor, may be important in the transition from fetal to extrauterine life. The change in level of nitric oxide during the early neonatal period has not been measured. Accordingly, the serum levels of nitric oxide metabolites (the sum of nitrite and nitrate) and plasma endothelin-1 were determined in 20 healthy neonates at birth, at 12 and 24 h postnatally, and at the age of 5 d. The lowest serum concentration of nitric oxide metabolites was observed at birth (26.2 ± 9.1 µmol 1^-1, mean ± SD) and increased with age, whereas the highest plasma concentration of endothelin-1 was observed at birth (14.0 ± 6.7 pg ml^-1) and decreased with age. These changes suggest that nitric oxide and endothelin-1 play roles in the circulatory adaptation of the neonate to extrauterine life.     

Free fatty acids and triglycerides in normoglycemic low birth weight newborns in early neonatal period

Free fatty acids, triglycerides and blood sugar were estimated in 45 lowbirth weight which included 24 preterm and 21 small for gestational age term babies, in the cord blood, in the fasting state at 6±1 h of age, and after initiation of sugar water feeds at 24±2 h of age. Thirty six appropriate for gestational age, term newborns were taken as controls. None of the newborns were born to diabetic mothers or had hypoglycemia. Mean cord blood sugar levels in all the groups were similar ranging between 69.55 to 73.7 mg/dl. followed by a fall in all at 6±1 h and subsequent rise at 24±2h. levels were significantly lower in LBW newborns compared to controls. Means FFA levels were lowest in babies with agestation of 28–32 weeks (0.27 m Mol/L), being almost similar to controls (0.35 mMol/L) in preterm 33–36 weeks (0.32 mMol/L) and higher than controls in SGA (0.48 mMol/L). An inverse relationship with blood sugar level was seen in serial estimations. SGA neonates continued to show higher and preterm (28–32 weeks) lowest levels throughout the study period. Triglycerides in cord blood were 36.72 mg/dl, 38.33 mg/dl, 56.23 mg/dl and 40.11 mg per cent in preterm 28–32 weeks, 33–36 weeks, SGA term and controls respectively. Levels showed a steady rise during the study period.     

The pattern of major serum apolipoproteins during the early neonatal period

Serum triglycerides, total cholesterol, lipoproteins and apolipoprotein A-I, B and C-III were investigated in 24 normal newborns at birth (umbilical cord blood) and again 4 days after birth (venous blood). Blood samples from 95 fasted normolipidemic male and female subjects aged between 20 to 60 years were also analysed. Immunochemical studies of serum from umbilical cord blood have shown that all investigated apolipoproteins were present although at lower levels than found in adults. The concentration of lipids, lipoproteins and apolipoprotein B and C-III in the serum from blood collected 4 days after birth did not practically differ from that of adult.     

Intestinal blood-flow velocity in uncomplicated preterm infants during the early neonatal period

Background. Intestinal blood-flow changes after birth. Objective. To elucidate the factors influencing intestinal blood-flow velocity in preterm infants during the early neonatal period. Materials and methods. We measured blood-flow velocity in the superior mesenteric artery by pulsed Doppler US in 44 uncomplicated infants with a gestational age of less than 34 weeks and from 1 to 6 days of age. Results. Time-averaged mean blood-flow velocity significantly increased with age from 1 to 6 days old. There was a significant correlation of time-averaged mean blood-flow velocity with birth weight at 1, 2, 4, 5 and 6 days of age and with the amount of enteral feeding from 4 to 6 days of age. Multivariate analysis showed that partial correlation of time-averaged mean blood-flow velocity with birth weight at 2 days of age and that with the amount of enteral feeding at 5 days of age were significant. End-diastolic blood-flow velocity was significantly lower at 1 day of age in infants with patent ductus arteriosus than those without it. Conclusions. Age, birth weight, the amount of enteral feeding and patent ductus arteriosus are included in the determinants of intestinal blood-flow velocity in preterm infants. Received: 27 February 1998 Accepted: 30 November 1998     

Exposure to marijuana during pregnancy alters neurobehavior in the early neonatal period

OBJECTIVE: To assess the neurobehavior of full-term neonates of adolescent mothers exposed to marijuana during pregnancy. STUDY DESIGN: This prospective cross-sectional study included full-term infants within 24 to 72 hours of life born to adolescent mothers at a single center in Brazil. Data on sociodemographic and obstetrical and neonatal characteristics were collected. The mothers underwent the Composite International Diagnostic Interview, and the infants were assessed with the Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS). Maternal hair and neonatal meconium were analyzed. Neonates exposed in utero to tobacco, alcohol, cocaine, and/or any other drugs except marijuana were excluded. RESULTS: Of 3685 infants born in the study hospital, 928 (25%) were born to adolescent mothers. Of these, 561 infants met the inclusion criteria and were studied. Marijuana exposure was detected in 26 infants (4.6%). Infants exposed (E) or not exposed (NE) to marijuana differed in the following NNNS variables: arousal (E, 4.05 +/- 1.19 vs NE, 3.68 +/- 0.70), regulation (E, 5.75 +/- 0.62 vs NE, 6.04 +/- 0.72), and excitability (E, 3.27 +/- 1.40 vs NE, 2.40 +/- 1.57). After controlling for confounding variables, the effect of marijuana exposure on these scores remained significant. CONCLUSIONS: Marijuana exposure during pregnancy alters the neurobehavioral performance of term newborn infants of adolescent mothers.     

Spontaneous labor increases nitric oxide synthesis during the early neonatal period

BACKGROUND: This paper aimed to assess the influence of spontaneous labor upon endogenous nitric oxide (NO) and endothelin 1 (ET-1) during transition to extrauterine life. METHODS: The serum levels of NO metabolites (the sum of nitrites and nitrates (NOx)) and the plasma level of ET-1 were determined in 53 healthy full-term infants (spontaneous labor group; n=40, cesarean delivery group; n=13). In both groups, blood samples were obtained from a cord vein at birth and from a peripheral vein at 5 days of age. RESULTS: The differences in serum NOx concentrations between the spontaneous labor group and the elective cesarean group were not significant at birth. By the age of 5 days, serum NOx concentrations had risen significantly in the spontaneous labor group to become significantly higher in the elective cesarean group. CONCLUSION: It is speculated that spontaneous labor might enhance endogenous NO synthesis at 5 days of age.     

Loose stools in the early neonatal period.

During a two-year period, the various factors associated with loose stools in the early neonatal period were studied among hospital born babies. Low birth weight babies had a lower incidence of non-infective loose stools when compared to neonates with a birth weight of more than 2500 g (p < 0.001). Newborns delivered by Cesarean section (p < 0.001) and those born to women with more than two children (p < 0.02) had a greater frequency of loose stools. Initiation of supplementary feeding and administration of antibiotics were important factors in causing loose stools. Bacterial etiology could be found only in 9.3% of newborns having loose stools. A later onset of loose stools was noted in those, whose stool culture grew bacterial organisms. Only nine newborns with loose stools required antibiotic therapy. Although loose stools were less common among low birth weight babies, they often required treatment with antimicrobials. None of them developed any complications. Since majority of them are non-bacterial and non-infective, great caution must be exercised before administering antibiotics to newborns with loose stools.     

Evolution of systemic arterial blood pressure during neonatal period in term newborns adequate for gestacional age

The authors studied the levels and evolution of systolic, mean and diastolic arterial blood pressure in term newborns adequate for gestacional age during the first month of life. The applied technique was oscillometric, using a non-invasive monitor. The study was prospective, including newborns who had received first minute Apgar score above 6, with no clinical disturbances or use of any drug with possible arterial blood pressure side effects. The measurements of systolic, mean and diastolic arterial blood pressure were taken at 12 hours of life and 3rd, 7th, 14th and 28th days of life. The authors observed an increase in arterial blood pressure mean values from the 1st to the 7th day of life and that there was no significant changes on the same measurements from the 1st to the 4th week of life.     

Effect of postnatal hypoxia on ammonia metabolism during the early neonatal period in the rat

The effect of experimental hypoxia on blood glutamine, glutamate, urea, ammonia, allantoin, hypoxanthine, xanthine, urate, orotate and lactate concentrations and on PO2, PCO2 and pH in term delivered newborn rats during the first 4 h after delivery were studied. Hypoxia increased blood glutamine, glutamate, allantoin and 'xanthines' (hypoxanthine + xanthine + uric acid) concentrations but decreased blood urea and ammonia concentrations. These results suggest that hypoxia inhibited ureogenesis by decreasing the ammonia available for urea synthesis.     

Evolution of serum C3, IgG, IgA and IgM levels of healthy mothers and their mature newborns during the early neonatal period

Susceptibility to infections is most pronounced during the perinatal period. The main characteristic feature of the clinical course is a proneness to generalisation; this can be attributed to immaturity of the immune system. In addition to a series of laboratory parameters, quick and exact determinations of immunoglobulins and complement fractions repeatedly performed within a short time may be useful in confirming a suspected infection and in following the course of the disease. In order to establish the normal basal levels and the dynamics of changes 30 mothers, all healthy, having no abnormality during pregnancy or shortly after delivery, and their healthy mature neonates were examined for IgG, IgA, IgM and C3 serum levels. These basal values are useful in judging the parameters under pathological conditions.     

Hormonal diagnosis of endocrinopathies in the early neonatal period

Based on the summarization of the results of hormonal examination of the newborn during the early neonatal period it has been revealed that early diagnosis of endocrinopathies can only be made with the use of the laboratory measurements of the concentrations of the appropriate hormones. For early diagnosis of congenital endocrine diseases the screening made according to the specific hormonal test is the most effective approach. It is necessary to differentiate between alterations associated with congenital endocrine diseases and transitory hormonal reactions due to the derangement of the child's status in the ante-, intra- or postnatal periods.