Intrapartum GBS screening and antibiotic prophylaxis: a European consensus conference

Group B streptococcus (GBS) remains worldwide a leading cause of severe neonatal disease. Since the end of the 1990s, various strategies for prevention of the early onset neonatal disease have been implemented and have evolved. When a universal antenatal GBS screening-based strategy is used to identify women who are given an intrapartum antimicrobial prophylaxis, a substantial reduction of incidence up to 80% has been reported in the USA as in other countries including European countries. However recommendations are still a matter of debate due to challenges and controversies on how best to identify candidates for prophylaxis and to drawbacks of intrapartum administration of antibiotics. In Europe, some countries recommend either antenatal GBS screening or risk-based strategies, or any combination, and others do not have national or any other kind of guidelines for prevention of GBS perinatal disease. Furthermore, accurate population-based data of incidence of GBS neonatal disease are not available in some countries and hamper good effectiveness evaluation of prevention strategies. To facilitate a consensus towards European guidelines for the management of pregnant women in labor and during pregnancy for the prevention of GBS perinatal disease, a conference was organized in 2013 with a group of experts in neonatology, gynecology-obstetrics and clinical microbiology coming from European representative countries. The group reviewed available data, identified areas where results were suboptimal, where revised procedures and new technologies could improve current practices for prevention of perinatal GBS disease. The key decision issued after the conference is to recommend intrapartum antimicrobial prophylaxis based on a universal intrapartum GBS screening strategy using a rapid real time testing.

Investigations for neonatal seizures

Seizures during the neonatal period are always medical emergencies. Apart from the need for rapid anticonvulsive treatment, the underlying condition is often not immediately obvious. In the search for the correct diagnosis, a thorough history, clinical examination, laboratory work-up, neurophysiological and neuroradiological investigations are all essential. A close collaboration between neonatologists, neuropaediatricians, laboratory specialists, neurophysiologists and radiologists facilitates the adequate care of the infant.

Investigating the European perspective of neonatal point-of-care echocardiography in the neonatal intensive care unit--a pilot study

Point-of-care functional neonatal echocardiography (fnECHO) is increasingly used to assess haemodynamic status or patency of the ductus arteriosus (PDA). In Australasia, 90 % of neonatal intensive care units (NICUs) practice point-of-care fnECHO. The Australian Society of Ultrasound Medicine offers a training certificate for fnECHO. In Europe, the use and indications of fnECHO and the extent of point-of-care fnECHO training and accreditation are unknown. We aimed to assess utilisation and training of fnECHO in Europe. For this, we conducted an email survey of 45 randomly chosen tertiary NICUs in 17 European countries. The recall rate was 89 % (n = 40). Neonatologists with skills in fnECHO worked in 29 NICUs (74 %), but paediatric cardiologists would routinely perform most fnECHOs. Twenty-four-hour echocardiography service was available in 31 NICUs (78 %). Indications for fnECHO included assessment of haemodynamic volume status (53 %), presence or absence of pulmonary hypertension of the neonate (55 %), indication for and effect of volume replacement therapy (58 %), PDA assessment and monitoring of PDA treatment (80 %). Teaching of fnECHO was offered to trainees in 22 NICUs (55 %). Teaching of fnECHO was provided by paediatric cardiologists (55 %) or by neonatologists (45 %). Only six (15 %) national colleges accredited fnECHO teaching courses.

CONCLUSION

fnECHO is widely practiced by neonatologists across Europe for a broad range of clinical questions. However, there is a lack of formal training and accreditation of fnECHO skills. This could be addressed by designing a dedicated European fnECHO training programme and by agreeing on a common European certificate of fnECHO.

The quality of the outdoor environment influences childrens health -- a cross-sectional study of preschools

AIM

To test how the quality of the outdoor environment of child day care centres (DCCs) influences children's health.

METHODS

The environment was assessed using the Outdoor Play Environmental Categories (OPEC) tool, time spent outdoors and physical activity as measured by pedometer. 172/253 (68%) of children aged 3.0-5.9 from nine DCCs participated in Southern Sweden. Health data collected were body mass index, waist circumference, saliva cortisol, length of night sleep during study, and symptoms and well-being which were scored (1-week diary - 121 parent responders). Also, parent-rated well-being and health of their child were scored (questionnaire, 132 parent responders). MANOVA, ANOVA and principal component analyses were performed to identify impacts of the outdoor environment on health.

RESULTS

High-quality outdoor environment at DCCs is associated with several health aspects in children such as leaner body, longer night sleep, better well-being and higher mid-morning saliva cortisol levels.

CONCLUSION

The quality of the outdoor environment at DCCs influenced the health and well-being of preschool children and should be given more attention among health care professionals and community planners.

Cranial ultrasound and MRI at term age in extremely preterm infants

OBJECTIVES

Conventional MRI at term age has been reported to be superior to cranial ultrasound (cUS) in detecting white matter (WM) abnormalities and predicting outcome in preterm infants. However, in a previous study cUS was performed during the first 6 weeks only and not in parallel to MRI at term age. Therefore, the aim of the present work was to study brain injuries in preterm infants performing concomitant cUS and MRI at full-term age.

METHODS

In a population-based cohort of 72 extremely low gestational age infants paired cUS and conventional MRI were performed at term age. Abnormalities on MRI were graded according to a previously published scoring system. On cUS images the lateral ventricles, the corpus callosum, the interhemispheric fissure and the subarachnoidal spaces were measured and the presence of cysts, grey matter abnormalities and gyral folding were scored.

RESULTS

Moderate or severe WM abnormalities were detected on MRI in 17% of infants and abnormalities of the grey matter in 11% of infants. Among infants with normal ultrasound (n=28, 39%) none had moderate or severe WM abnormalities or abnormal grey matter on MRI. All infants with severe abnormalities (n=3, 4%) were identified as severe on MRI and cUS.

CONCLUSIONS

All severe WM abnormalities identified on MRI at term age were also detected by cUS at term, providing the examinations were performed on the same day. Infants with normal cUS at term age were found to have a normal MRI or only mild WM abnormalities on MRI at term age.

Approach to seizures in the neonatal period: a European perspective

In the neonatal period, seizures rank among the most common neurological symptoms, often indicating an underlying serious neurological condition. It is remarkable that although new tools have been incorporated into the diagnosis of neonatal seizures, there is no consensus about the therapeutic approach among different doctors and institutions. Hence, although phenobarbital is still considered the initial drug of choice, the protocols reported in the literature show a great variability in the approach to treatment of refractory seizures. We used a questionnaire to gain information regarding the treatment of seizures in the neonatal period in different European institutions.

CONCLUSION

We conclude that phenobarbital is still the initial drug of choice followed by benzodiazepines, except in preterm infants with a birth weight below 1800 g. In refractory seizures, the use of continuous lidocaine infusion is most common. Of note, clinical studies with newer drugs have been mostly performed in the United States but not in Europe.

The prognostic value of early aEEG in asphyxiated infants undergoing systemic hypothermia treatment

BACKGROUND

Induced moderate hypothermia (HT) for 72 h has been shown to reduce the combined outcome of death or severe neurodevelopmental disabilities in asphyxiated full-term infants. A pathological amplitude integrated EEG background as early as 3-6 h after birth, has been shown to correlate to poor prognosis.

AIM

The aim of this study was to investigate the correlation between amplitude integrated EEG during HT treatment and short-term outcome in asphyxiated full-term infants with moderate/severe hypoxic-ischaemic encephalopathy.

METHODS

Between December 2006 and December 2007, 24 infants were treated with moderate HT (33.5 degrees C for 72 h) using a cooling mattress. Motor functions were assessed at 4 and 12 months of age.

RESULTS

Of the total birth cohort of 28,837 infants, 26 infants fulfilled the criteria for HT treatment (0.9/1000) of whom 23 was treated with HT and all of these infants had available amplitude integrated EEG data. Normal 1-year outcome was found in 10/15 infants with severely abnormal burst-suppression pattern or worse at 6 h of age. Severe abnormalities were found to be significantly predictive for abnormal outcome after 36 h.

CONCLUSION

Among asphyxiated infants treated with HT, only those who had aEEG abnormalities persisting at and beyond 24 h after birth showed poor neurological outcome at 1 year.

Early surfactant administration with brief ventilation vs. selective surfactant and continued mechanical ventilation for preterm infants with or at risk for respiratory distress syndrome

BACKGROUND

Both prophylactic and early surfactant replacement therapy reduce mortality and pulmonary complications in ventilated infants with respiratory distress syndrome (RDS) compared with later selective surfactant administration. However, continued post-surfactant intubation and ventilation are risk factors for bronchopulmonary dysplasia (BPD). The purpose of this review was to compare outcomes between two strategies of surfactant administration in infants with RDS; prophylactic or early surfactant administration followed by prompt extubation, compared with later, selective use of surfactant followed by continued mechanical ventilation.

OBJECTIVES

To compare two treatment strategies in preterm infants with or at risk for RDS: early surfactant administration with brief mechanical ventilation (less than one hour) followed by extubation vs. later selective surfactant administration, continued mechanical ventilation, and extubation from low respiratory support. Two populations of infants receiving early surfactant were considered: spontaneously breathing infants with signs of RDS (who receive surfactant administration during evolution of RDS prior to requiring intubation for respiratory failure) and infants at high risk for RDS (who receive prophylactic surfactant administration within 15 minutes after birth).

SEARCH STRATEGY

Searches were made of the Oxford Database of Perinatal Trials, MEDLINE (1966 - December 2006), CINAHL (1982 to December Week 2, 2006), EMBASE (1980 - December 2006), Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2006), Pediatric Research (1990 - 2006), abstracts, expert informants and hand searching. No language restrictions were applied.

SELECTION CRITERIA

Randomized or quasi-randomized controlled clinical trials comparing early surfactant administration with planned brief mechanical ventilation (less than one hour) followed by extubation vs. selective surfactant administration continued mechanical ventilation, and extubation from low respiratory support.

DATA COLLECTION AND ANALYSIS

Data were sought regarding effects on the incidence of mechanical ventilation (ventilation continued or initiated beyond one hour after surfactant administration), incidence of bronchopulmonary dysplasia (BPD), chronic lung disease (CLD), mortality, duration of mechanical ventilation, duration of hospitalization, duration of oxygen therapy, duration of respiratory support (including CPAP and nasal cannula), number of patients receiving surfactant, number of surfactant doses administered per patient, incidence of air leak syndromes (pulmonary interstitial emphysema, pneumothorax), patent ductus arteriosus requiring treatment, pulmonary hemorrhage, and other complications of prematurity. Stratified analysis was performed according to inspired oxygen threshold for early intubation and surfactant administration in the treatment group: inspired oxygen within lower (FiO2< 0.45) or higher (FiO2 > 0.45) range at study entry. Treatment effect was expressed as relative risk (RR) and risk difference (RD) for categorical variables, and weighted mean difference (WMD) for continuous variables.

MAIN RESULTS

Six randomized controlled clinical trials met selection criteria and were included in this review. In these studies of infants with signs and symptoms of RDS, intubation and early surfactant therapy followed by extubation to nasal CPAP (NCPAP) compared with later selective surfactant administration was associated with a lower incidence of mechanical ventilation [typical RR 0.67, 95% CI 0.57, 0.79], air leak syndromes [typical RR 0.52, 95% CI 0.28, 0.96] and BPD [typical RR 0.51, 95% CI 0.26, 0.99]. A larger proportion of infants in the early surfactant group received surfactant than in the selective surfactant group [typical RR 1.62, 95% CI 1.41, 1.86]. The number of surfactant doses per patient was significantly greater among patients randomized to the early surfactant group [WMD 0.57 doses per patient, 95% CI 0.44, 0.69]. In stratified analysis by FIO2 at study entry, a lower threshold for treatment (FIO2< 0.45) resulted in lower incidence of airleak [typical RR 0.46 and 95% CI 0.23, 0.93] and BPD [typical RR 0.43, 95% CI 0.20, 0.92]. A higher treatment threshold (FIO2 > 0.45) at study entry was associated with a higher incidence of patent ductus arteriosus requiring treatment [typical RR 2.15, 95% CI 1.09, 4.13].

AUTHORS' CONCLUSIONS

Early surfactant replacement therapy with extubation to NCPAP compared with later selective surfactant replacement and continued mechanical ventilation with extubation from low ventilator support is associated with less need mechanical ventilation, lower incidence of BPD and fewer air leak syndromes. A lower treatment threshold (FIO2< 0.45) confers greater advantage in reducing the incidences of airleak syndromes and BPD; moreover a higher treatment threshold (FIO2 at study > 0.45) was associated with increased risk of PDA. These data suggest that treatment with surfactant by transient intubation using a low treatment threshold (FIO2< 0.45) is preferable to later, selective surfactant therapy by transient intubation using a higher threshold for study entry (FIO2 > 0.45) or at the time of respiratory failure and initiation of mechanical ventilation.

Implementation of surfactant treatment during continuous positive airway pressure

OBJECTIVE

To study the effects of implementing a method for surfactant administration by transient intubation, INSURE (i.e. INtubation SURfactant Extubation) during nasal continuous positive airway pressure (nCPAP) for moderately preterm infants with respiratory distress syndrome (RDS).

STUDY DESIGN

A descriptive, retrospective, bi-center study in Stockholm, Sweden, comparing mechanical ventilation (MV) rates, surfactant use, treatment response and outcome of all inborn infants with gestational age 27 to 34 weeks and RDS, (n=420), during the 5-year periods before and after the introduction of the INSURE-strategy at one of the centers (Karolinska Huddinge) in 1998. The other center (Karolinska Solna) continued conventional surfactant therapy in conjunction with MV throughout the study.

RESULTS

Implementation of INSURE at Karolinska Huddinge reduced the number of infants requiring MV by 50% (P<0.01), resulted in earlier surfactant administration and increased overall surfactant use. INSURE-treatment improved oxygenation and the treatment response was sustained over time with only 17% of the infants requiring >1 dose of surfactant. At Karolinska Solna, the MV rates were unaltered between the first and second 5-year period.

CONCLUSION

Implementing a strategy of surfactant administration by transient intubation during nCPAP reduces the need for MV without adverse effects on outcome and may be an option to more effectively treat RDS, particularly in a care setting where transfer is necessary to provide MV.

Helicobacter pylori eradication in children and adolescents by a once daily 6-day treatment with or without a proton pump inhibitor in a double-blind randomized trial

AIM

To evaluate two simplified Helicobacter pylori eradication treatment alternatives for children and adolescents.

METHODS

Study subjects were identified by enzyme-linked immunosorbent assay and immunoblot in a family screening project. Helicobacter pylori infected 10-21 year olds were offered treatment, individuals with abdominal pain underwent upper endoscopy and those with peptic ulcers were excluded. Participants were randomized to either azithromycin 500 mg daily and tinidazole 500 mg two tablets daily in combination with lansoprasole 30 mg daily for 6 days (ATL-group) or with placebo (ATP-group). Urea Breath Test was performed at inclusion and after a minimum of 6 weeks after end of therapy.

RESULTS

In total, 131 individuals were randomized, of whom 31 (24%) had undergone upper endoscopy. Full compliance was achieved in 93% (122 of 131). The intention-to-treat eradication rate was 67% (44 of 66) and 58% (38 of 65) for the ATL- and the ATP-group, respectively.

CONCLUSION

The double-blind randomized clinical trial did not identify a simplified, successful once daily H. pylori treatment for children and adolescents. Thus, twice daily proton pump inhibitor (PPI)-based triple therapies for 7 days remain as the choice of treatment in children. Further, powerful and controlled studies are needed to elucidate the best treatment strategies for H. pylori eradication in this age group.

Early surfactant administration with brief ventilation vs selective surfactant and continued mechanical ventilation for preterm infants with or at risk for respiratory distress syndrome

BACKGROUND

Both prophylactic and early surfactant replacement therapy, compared with later selective surfactant administration, reduce mortality and pulmonary complications in ventilated infants with respiratory distress syndrome (RDS). However, continued post-surfactant intubation and ventilation are risk factors for chronic lung disease. Whether prophylactic or early surfactant administration followed by prompt extubation, compared with later, selective use of surfactant followed by continued mechanical ventilation reduces the need for mechanical ventilation and the incidence of chronic lung disease is unknown.

OBJECTIVES

To compare two treatment strategies in preterm infants with, or at risk for, RDS: early surfactant administration with brief mechanical ventilation (less than one hour) followed by extubation, vs later, selective surfactant administration, continued mechanical ventilation and extubation from low respiratory support. Two populations of infants receiving early surfactant were considered: spontaneously breathing infants with signs of RDS (surfactant administration during evolution of RDS prior to requiring intubation for respiratory failure) and infants at high risk for RDS (prophylactic surfactant administration within 15 minutes after birth).

SEARCH STRATEGY

Searches were made of the Oxford Database of Perinatal trials, MEDLINE (1966-December 2003), CINAHL (1982-December 2003), EMBASE (1980-December 2003), Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2004), Pediatric Research (1990-2003), abstracts, expert informants and hand searching. No language restrictions were applied.

SELECTION CRITERIA

Randomized or quasi-randomized controlled clinical trials comparing early surfactant administration with planned brief mechanical ventilation (less than one hour) followed by extubation, vs selective surfactant administration, continued mechanical ventilation and extubation from low respiratory support.

DATA COLLECTION AND ANALYSIS

Data were sought regarding effects on incidence of mechanical ventilation (ventilation continued or initiated beyond one hour after surfactant administration), incidence of bronchopulmonary dysplasia (BPD), chronic lung disease (CLD), mortality, duration of mechanical ventilation, duration of hospitalization, time in oxygen, duration of respiratory support (including CPAP and nasal cannula), number of patients receiving surfactant, number of surfactant doses administered per patient, incidence of air leak syndromes (pulmonary interstitial emphysema, pneumothorax), patent ductus arteriosus requiring treatment, pulmonary hemorrhage, and other complications of prematurity. Treatment effect was expressed as relative risk (RR) and risk difference (RD) for categorical variables, and weighted mean difference (WMD) for continuous variables.

MAIN RESULTS

Four randomized controlled clinical trials met selection criteria and were included in this review. In these studies of infants with signs of RDS, intubation and early surfactant therapy followed by extubation to nasal CPAP (NCPAP) compared with later selective surfactant administration was associated with a lower incidence of mechanical ventilation [typical RR 0.70, 95% CI 0.59, 0.84]. None of the trials reported a significant difference in the incidence of BPD or CLD; however, meta-analysis for this outcome cannot yet be performed because the primary data from three of the trials have not yet been published in full. A larger proportion of infants in the early surfactant group received surfactant than in the selective surfactant group [typical RR 1.59, 95% CI 1.35, 1.88]. The number of surfactant doses per patient was significantly greater among patients randomized to the early surfactant group [WMD 0.51 doses per patient, 95% CI 0.36, 0.65]. Trends towards a decreased incidence of air leak syndromes (two studies) and a higher incidence of patent ductus arteriosus requiring treatment (one study) were seen in the early surfactant group. There was no evidence of effect on time in oxygen or duration of mechanical ventilation.

REVIEWERS' CONCLUSIONS

Early surfactant replacement therapy with extubation to NCPAP compared with later, selective surfactant replacement and continued mechanical ventilation with extubation from low ventilator support is associated with a reduced need for mechanical ventilation and increased utilization of exogenous surfactant therapy. There is insufficient evidence at present to reliably evaluate effect on BPD or CLD.

Cytokine response in cerebrospinal fluid from preterm infants with posthaemorrhagic ventricular dilatation

AIM

Posthaemorrhagic ventricular dilatation (PHVD) is closely associated with white matter damage and neurological disability in the preterm infant. Proinflammatory cytokines have been implicated in the pathogenesis of white matter injury and subsequent cerebral palsy. The aim of this study was to determine the levels of proinflammatory cytokines in cerebrospinal fluid (CSF) from preterm infants with PHVD and to correlate the levels to white matter damage and neurodevelopmental outcome.

METHODS

CSF samples were obtained from 24 preterm infants with expanding PHVD and 19 preterm infants with normal ultrasound. Tumour necrosis factor-alphaa (TNF-alpha ), interleukin-1beta (IL-1beta), interleukin-8 (IL-8) and interferon-gamma (IFN-gamma) in CSF were measured by enzyme-linked immunosorbent assay, and IL-6 was measured by bioassay.

RESULTS

The concentrations of TNF-alpha, IL-1beta, IL-6 and IL-8 were significantly elevated in CSF from infants with PHVD. TNF-alpha was detected in 43% of PHVD infants and 11% of controls (p = 0.04). IL-1beta was detected in 67% of PHVD infants and 0% of controls (p < 0.0001). The concentrations of IL-6 were 368 (145-460) pg ml(-1) in the PHVD group and 30 (25-41) pg ml(-1) in the control group (p < 0.0001), and those of IL-8 were 3000 (1620-3400) pg ml(-1) in the PHVD group and 35 (0-230) pg ml(-1) in the control group (p < 0.0001). Cytokine concentrations did not correlate with white matter lesions on ultrasound, shunt dependence or neurological outcome within the PHVD group.

CONCLUSION

There was an intense and prolonged inflammatory reaction in CSF from preterm infants with PHVD and a high risk for subsequent white matter injury and permanent neurological impairment.

Early surfactant administration with brief ventilation vs selective surfactant and continued mechanical ventilation for preterm infants with or at risk for RDS

BACKGROUND

Both early and prophylactic surfactant replacement therapy compared with later selective surfactant administration reduces mortality and pulmonary complications in ventilated infants with respiratory distress syndrome (RDS). Continuous distending pressure (CDP) has also been shown to improve clinical outcomes in preterm infants with RDS.

OBJECTIVES

To compare two treatment strategies in preterm infants with, or at risk for, RDS: early surfactant administration with brief mechanical ventilation (less than 1 hour) followed by extubation, vs later, selective surfactant administration, continued mechanical ventilation and extubation from low respiratory support. Two populations of infants receiving early surfactant were considered: spontaneously breathing infants with signs of RDS (surfactant administration during evolution of RDS prior to requiring intubation for respiratory failure) and infants at high risk for RDS (prophylactic surfactant administration within 15 minutes after birth).

SEARCH STRATEGY

Searches were made of the Oxford Database of Perinatal trials, MEDLINE (1966-December 2001), CINAHL (1982-December 2001), EMBASE (1980-December 2001), Cochrane Controlled Trials Register (The Cochrane Library, Issue 1, 2002), Pediatric Research (1990-2001), abstracts, expert informants and hand searching. No language restrictions were applied.

SELECTION CRITERIA

Randomized or quasi-randomized controlled clinical trials comparing early surfactant administration with planned brief mechanical ventilation (less than one hour) followed by extubation, vs selective surfactant administration, continued mechanical ventilation and extubation from low respiratory support.

DATA COLLECTION AND ANALYSIS

Data were sought regarding effects on incidence of mechanical ventilation (ventilation continued or initiated beyond one hour after surfactant administration), incidence of bronchopulmonary dysplasia (BPD, need for oxygen at 28 days of age), incidence of chronic lung disease (CLD, need for oxygen at 36 weeks' post-conceptional age), mortality (neonatal mortality < 28 days and mortality prior to hospital discharge), duration of mechanical ventilation, duration of hospitalization, time in oxygen, duration of respiratory support (including CPAP and nasal cannula), number of patients receiving surfactant, number of surfactant doses administered per patient, incidence of air leak syndromes (pulmonary interstitial emphysema, pneumothorax), incidence of pulmonary hemorrhage, and other complications of prematurity. Data analyses were performed in accordance with the standards of the Cochrane Neonatal Review Group.

MAIN RESULTS

Only one randomized controlled clinical trial met selection criteria and was included in this review (Verder 1994). In this study of infants with signs of RDS, intubation and early surfactant therapy followed by extubation to nasal CPAP (NCPAP) compared with later, selective surfactant administration was associated with a lower incidence of mechanical ventilation (ventilation continuing for one hour or more after surfactant administration in the early surfactant group or initiated for respiratory insufficiency or apnea in either group [RR 0.51, 95% CI 0.32, 0.76]). A larger proportion of infants in the early surfactant group received surfactant than in the selective surfactant group [RR 1.74, 95% CI 1.30, 2.33]. The number of surfactant doses per patient was significantly greater among patients randomized to the early surfactant group [MD 0.51, 95% CI 0.32, 0.70]. Trends towards a decreased incidence of mortality, and a higher rate of patent ductus arteriosus requiring treatment were seen in the early surfactant group. There was no evidence of effect on median time in oxygen, duration of mechanical ventilation, or incidence of BPD (oxygen at 28 days).

REVIEWER'S CONCLUSIONS

Early surfactant replacement therapy with extubation to NCPAP compared with later, selective surfactant replacement and continued mechanical ventilation with extubation from low ventilator support is associated with a reduced need for mechanical ventilation and increased utilization of exogenous surfactant therapy. These conclusions are based on findings from one small randomized clinical trial. Additional randomized trials are needed and are underway.

Brain-specific proteins in the cerebrospinal fluid of severely asphyxiated newborn infants

Upcoming trials of neuroprotective strategies in severely asphyxiated newborn infants emphasize the need for early and objective markers of both good and bad long-term prognosis. Traditional markers such as neurological depression and seizures are not specific.

AIM

To study whether measurement in the cerebrospinal fluid of some proteins known to be specific to the central nervous system was in covariance with the clinical course and long-term prognosis.

METHODS

Twenty-two asphyxiated infants were included in the study and compared with a control group of 8 infants without signs of perinatal asphyxia. Cerebrospinal fluid (CSF) was collected during the first 4 d of life and analysed for neurofilament protein (NFp), glial fibrillary acidic protein (GFAp), protein S-100 and neuron-specific enolase (NSE).

RESULTS

The concentrations of all four proteins were significantly increased in the CSF of asphyxiated infants. The concentrations correlated significantly with other indicators of long-term prognosis and to neurological impairment at I y of age, or death before that time. Specifically, concentrations were excessively high in the five infants who died.

CONCLUSIONS

High concentrations of brain-specific proteins are released into the CSF of asphyxiated infants. It might therefore be useful to measure these concentrations when excluding patients with the gravest prognosis from neuroprotective trials.

Helicobacter pylori infection in Swedish school children: lack of evidence of child-to-child transmission outside the family

BACKGROUND & AIMS

Helicobacter pylori infection is mainly acquired in early childhood, but the exact routes of transmission remain elusive. To distinguish between risks of intrafamilial and extraneous child-to-child transmission, we studied H. pylori seroprevalence among Swedish school children with varying family backgrounds.

METHODS

In a cross-sectional study, 695 of 858 (81%) 10-12-year-olds in 36 school classes in Stockholm donated blood and answered a questionnaire. Infection was detected by enzyme-linked immunosorbent assay and confirmed by immunoblot and urea breath test.

RESULTS

Overall, 112 (16%) children were infected. The seroprevalence was 2% among 435 children with Scandinavian parents and 55% among 144 children with origin in high prevalence areas (Middle East and Africa). Among children born in Scandinavia, the odds ratios (adjusted for gender, socioeconomic status, and family size) for being seropositive were 39.1 (95% confidence interval, 16.7-91.3) and 5.6 (1.8-17.3) when having parents born in high and medium prevalence areas, respectively, relative to children with Scandinavian parents. Importantly, the prevalence of infection among the classmates was not a risk factor for H. pylori infection.

CONCLUSION

Our data indicate that intrafamilial transmission is far more important than child-to-child transmission outside the family. The H. pylori prevalence in the parental generation may be a crucial determinant for the child's risk of contracting the infection.

Brain specific proteins in posthaemorrhagic ventricular dilatation

Median neurofilament and glial fibrillary acidic protein concentrations in the cerebrospinal fluid of 18 infants with posthaemorrhagic ventricular dilatation were 20-200 times higher than control values. S-100 protein in cerebrospinal fluid was four times higher than control values. Glial fibrillary acidic protein concentrations correlated with death or disability and with parenchymal lesions but not with shunt dependence.

Non-protein-bound iron is elevated in cerebrospinal fluid from preterm infants with posthemorrhagic ventricular dilatation

Posthemorrhagic ventricular dilatation (PHVD) is closely associated with white matter injury and neurologic disability in the preterm infant. An important factor in periventricular white matter damage may be the specific vulnerability of iron-rich immature oligodendroglia to reactive oxygen species toxicity. Non-protein-bound iron (NPBI) is a potent catalyst in the generation of hydroxyl radicals (Fenton reaction). Our objective was to determine whether NPBI is increased in cerebrospinal fluid (CSF) from preterm infants with PHVD compared with preterm control infants. Samples of CSF were obtained from 20 infants with PHVD and 10 control subjects. The level of NPBI was determined by a new spectrophotometric method using bathophenanthroline as a chelator. To evaluate the effect of hemolysis, CSF and blood were mixed in different proportions, spun, frozen and thawed, and then analyzed for NPBI. NPBI was found in 75% (15 of 20) of infants with PHVD and in 0% (0 of 10) of control infants (p = 0.0002). Hemolysis induced in vitro did not result in any significant levels of NPBI. Within the group with PHVD, NPBI concentrations in CSF did not correlate with disability, parenchymal brain lesions, or the need for shunt surgery. NPBI was increased in CSF from preterm infants with PHVD, and the increase could not be explained by hemolysis alone. Free iron may help to explain the association between intraventricular hemorrhage and white matter damage.

Long-chain polyunsaturated fatty acids in human milk and brain growth during early infancy

Long-chain polyunsaturated fatty acids are essential for growth and development, and their crucial role in the development of the central nervous system and in retinal function has been the subject of many studies. As the balance between n-6 and n-3 fatty acids has to be optimal, their concentrations in the milk given to infants who are exclusively breastfed is of major importance. In this study, the composition of fatty acids in mothers' milk and the growth rate of the infant brain were analysed. Nineteen mother-term infant pairs from Stockholm, Sweden, were studied from birth to 1 mo and 3 mo of age, during which time the infants were breastfed exclusively. The dietary intake of the mothers was calculated and found to concur with the recommended daily dietary allowances of Swedish lactating women as regards energy, protein, fat and carbohydrates. The amounts of linoleic acid and alpha-linolenic acid in the diet were similar to those reported for European and North American women. The ratio between arachidonic acid (AA) and docosahexaenoic acid (DHA) in the milk from Swedish mothers is approximately the same as in the brain of infants, and was found to be positively correlated with the rate of gain of the occipito-frontal head circumference and of the calculated brain weight at 1 mo (p < 0.01) and 3 mo (p < 0.01) of age, respectively. However, further studies are needed to establish the exact requirements of AA and DHA for optimal growth and development during early infancy in exclusively breastfed infants.

Predictive value of fetal scalp blood lactate concentration and pH as markers of neurologic disability

OBJECTIVES

We aimed to analyze the predictive value of the fetal scalp blood lactate concentration and pH, especially in regard to outcome variables that are strong predictors of impaired long-term outcome. An additional aim was to establish cutoff lactate levels in fetal scalp blood.

STUDY DESIGN

We conducted a retrospective study of all patients who had fetal scalp blood sampling performed because of an ominous fetal heart rate pattern at Huddinge University Hospital from October 1993 to October 1998. Fetal scalp blood sampling was performed in 1709 patients. The pH and the lactate concentration were determined in fetal scalp blood of 1221 and 814 of these patients, respectively. Outcome variables included pH <7.0 in umbilical artery blood; base deficit >16.0 mmol/L in umbilical artery blood; Apgar scores <7 at 1 minute, <7 at 5 minutes, and <4 at 5 minutes; and hypoxic-ischemic encephalopathy.

RESULTS

Sensitivity and specificity were generally higher in the lactate group than in the pH group, particularly in relation to an Apgar score <4 at 5 minutes and moderate to severe hypoxic-ischemic encephalopathy. In 326 patients the scalp blood lactate concentration and pH value had been obtained at the same time, thus allowing a comparison between these methods. The areas under the receiver operating characteristic curves were significantly higher for the lactate concentration than for the pH value with 2 outcome variables: Apgar score <4 at 5 minutes (P =.033) and moderate to severe hypoxic-ischemic encephalopathy (P =.015).

CONCLUSIONS

Our findings suggest that determination of the lactate concentration in fetal scalp blood is a more sensitive diagnostic tool than is determination of the pH value for predicting either an Apgar score <4 at 5 minutes or moderate to severe hypoxic-ischemic encephalopathy. In previous studies we also showed lactate measurements to be more often successful than pH analysis. Therefore we consider the measurement of lactate in fetal scalp blood to be an attractive alternative to pH analysis, and determination of the lactate concentration in fetal scalp blood seems to be a useful tool for monitoring the condition of the fetus. A suitable cutoff limit for fetal scalp blood lactate concentration as an indicator of fetal asphyxia could be 4.8 mmol/L.

Clinical symptoms and social factors in a cohort of children spontaneously clearing Helicobacter pylori infection

In a cohort study of 305 Swedish children, repeated blood samples and structured questionnaires were obtained from 6 mo to 11 y of age. Of the 40 children seropositive for Helicobacter pylori in one or more samples, 32 (80%) had cleared the infection by 11 y of age. No association was found between H. pylori seropositivity at any time and reported antibiotic consumption, size of home and family, type of day-care, history of atopic disease, length of breastfeeding or peptic ulcer disease in the family. Girls reported more (p = 0.002) unspecified abdominal pain during childhood than boys, but the difference in H. pylori infection rate (15/150, 10% for boys and 25/144, 17% for girls) was not significantly different (p = 0.09). Unspecified abdominal pain during childhood was reported more often (OR adjusted for gender = 2.2, 95% CI = 1.0-4.4, p = 0.04) for the children seropositive at some point (17/39, 44%) than for the seronegative children (54/217, 25%). RAP at 11 y of age was more often reported by the 9/36 (25%) children seropositive at some time in life than by the 23/172 (13%) seronegatives, but the difference was not statistically significant (OR adjusted for gender = 2.0, 95% CI = 0.8-4.6, p = 0.1). The study shows that H. pylori seropositivity was associated with a parental report of unspecified abdominal pain during childhood. Also, a history of unspecified abdominal pain was more common (OR = 51.6, 95% CI = 15.6-220, p < 0.001) in children reporting RAP at 11 y of age.

A ten year follow-up after immunization with a two component acellular pertussis vaccine

OBJECTIVES

To investigate the duration of antitoxin response and immunity to pertussis 10 years after priming with either two or three doses of a two component acellular pertussis vaccine or with three doses of a whole cell vaccine and then boostered with the acellular vaccine.

SUBJECTS

At 11 years of age 207 of 304 (68%) children of the original cohort returned for a blood sample and 262 (86%) participated by answering a questionnaire.

METHODS

Neutralizing antibodies to pertussis toxin (antitoxin) were analyzed by the Chinese hamster ovary cell assay. Clinical pertussis and pertussis exposure were investigated by a structured questionnaire.

RESULTS

Measurable antitoxin was found in 77% of the samples, with no differences by type of vaccine or by the number of doses given for priming. A significant decrease of antibody concentration (P<0.001) was noted from the previous recall at 4 years of age, and significant titer rises were found for 14% of the children, irrespective of known exposure. Confirmed pertussis during follow-up, as defined in the study, was reported for 14 of 262 (5%) children.

CONCLUSIONS

The study showed that antitoxin concentrations are maintained in a situation of endemic pertussis and indicated that the long term protection after an acellular booster was good, irrespective of type of vaccine or the number of doses of acellular vaccine given for priming.

[Lung function in premature infants can be improved. Surfactant therapy and CPAP reduce the need of respiratory support]

Randomised trials have shown exogenous surfactant therapy to reduce mortality and morbidity among very low birthweight (VLBW) infants with respiratory distress syndrome (RDS). Surfactant therapy is normally given to infants on mechanical ventilation. In the Stockholm area, 12 VLBW infants born after 27-30 gestational weeks and suffering from RDS were recently treated using the INSURE (Intubation-SURfactant-Extubation) approach--i.e., surfactant therapy during brief intubation, immediately followed by extubation and continuous positive airway pressure (CPAP) treatment. The treatment was successful in all 12 cases, the mean (+/- SD) a/A ratio increasing significantly from 0.17 +/- 0.04 before the INSURE procedure to 0.46 (0.12 after (P < 0.001). Only one infant later needed mechanical ventilation for RDS.

Cytokine response in cerebrospinal fluid after birth asphyxia

Experimental studies suggest that cytokine-mediated inflammatory reactions are important in the cascade leading to hypoxic-ischemic brain injury. The purpose was to study the content of pro- and antiinflammatory cytokines in cerebrospinal fluid (CSF) of asphyxiated and control infants. Samples of CSF were obtained from 20 infants who fulfilled the criteria of birth asphyxia and from seven newborn control subjects. The concentrations of IL-1beta, IL-8, IL-10, tumor necrosis factor (TNF)-alpha, and granulocyte/monocyte colony-stimulating factor (GM-CSF) were determined with ELISA and of IL-6 using a bioassay. The concentration of IL-6 (pg/mL) was higher in asphyxiated (250, 35-543; median, interquartile range) than in control (0, 0-18) infants (p = 0.001). There was also a significant relationship between IL-6 and the degree of HIE, and between IL-6 and outcome. In addition, the content of IL-8 (pg/mL) was higher (p = 0.009) in the asphyxia group (170, 70-1440), than in the the control group (10, 0-30) and there was an association between IL-8 and degree of HIE. The levels of IL-10, TNF-alpha, GM-CSF, and IL-1beta did not differ between groups. In conclusion, the proinflammatory cytokines IL-6 and IL-8 were markedly elevated in CSF of asphyxiated infants, and the intrathecal levels of these cytokines corresponded to the degree of HIE.

Effects of hyperglycemia on gasping and autoresuscitation in newborn rats

The aim of this study was to test the effects of glucose on the gasping ability and survival in a rat pup model during acute anoxia. Newborn rat pups of both 1 and 8 days of age were given glucose (30 and 60 mg/animal) or saline intraperitoneally and subsequently subjected to anoxia (100% N2). Glucose supplement induced hyperglycemia. Respiration was recorded by barometric plethysmography. The rat pups responded to acute anoxia with a robust sequence of respiratory pattern: hyperpnea, primary apnea, hypoxic gasping and secondary apnea. During anoxia the 1-day-old rats gasped much longer than the 8-day-old rats (23.4 +/- 1.0 vs. 6.1 +/- 0.5 min, p < 0.001). No difference was found in gasping duration between the saline control and the glucose-supplemented 1-day-old rat pups. The 8-day-old supplemented rats gasped much longer (9.3 +/- 0.5 min) than the control rats (6.1 +/- 0.5 min, p < 0.01). The animals autoresuscitated when they received oxygen (100%) during the gasping period. When oxygen was given after the gasping period, the survival rate was 33.3% in control and 0% in supplemented 1-day-old rats, and 100% in control and 50% in glucose-supplemented 8-day-old rats (p < 0.02). Further controlled experiments for a fixed period of anoxia to 13.5 min resulted in survival rates of 50.0% for controls and 28.6% for supplemented animals, respectively. The overall survival rate was then 85.2% in control and 52.9% in supplemented 8-day-old rats (p < 0.05). Lactate concentration in blood rapidly increased in the first 6 min of anoxia and thereafter gradually increased to 22.1 mmol/l around the last gasp in the 1-day-old rats. Hyperglycemia did not cause further accumulation of lactate despite a transient elevation over the control rats at 6 min of anoxia. In the 8-day-old supplemented animals the lactate level was only modestly increased, probably due to the prolonged gasping period. In conclusion, we found that gasping performance was well preserved in the 8-day-old glucose-supplemented rats, whereas the autoresuscitation mechanism after the last gasp might be altered due to hyperglycemia. In addition, the accumulation of lactate in the blood did not affect the gasping performance and the mechanisms of autoresuscitation.

Immunoglobulin E and G responses to pertussis toxin in children immunised with adsorbed and non-adsorbed whole cell pertussis vaccines

The IgE and IgG responses to pertussis toxin were measured in blood samples from 70 children (age 1.5-2.9 years) after primary immunisation with either a non-aluminium adsorbed, whole cell vaccine (n = 34) or an aluminium adsorbed whole cell vaccine (n = 36). Two years later, they received a booster immunisation with either the non-adsorbed (n = 24) or the aluminium adsorbed vaccine (n = 14). Neutralising antibodies to pertussis toxin were higher (P < 0.05) after the three priming doses of the adsorbed vaccine than of the non-adsorbed vaccine, although both groups showed > 90% seropositives after the third dose. IgE antibodies to PT (PT-IgE) were detected in samples from 11/52 children after completed primary immunisation and the levels were low (median < or = 0.1 PRU ml-1) in both groups. No significant differences between the groups were found. PT-IgE levels did not increase after the booster injection. Thus, the aluminium content of the whole cell vaccines influenced the IgG response but not the IgE responses to pertussis toxin. The high rates of PT-IgE responses noted after a booster dose of acellular or whole cell pertussis vaccine to children primed with acellular vaccine in previous studies can therefore be mainly ascribed to the nature of the priming vaccine rather than the aluminium adjuvant.

Seroepidemiology of Helicobacter pylori infection in a cohort of children monitored from 6 months to 11 years of age

A cohort of Swedish children was monitored from 6 months to 11 years of age. Immunoglobulin G (IgG) and IgA antibodies to Helicobacter pylori were measured in 1,857 serum samples, drawn at the ages of 6, 8, 10, 18 months and 2, 4, and 11 years. Of the 294 children, 40 (13.6%) were found to have been infected at some time. However, at 11 years of age, only 6 of 201 (3%) children were seropositive. The highest seroprevalence of positive results, 10%, was found at 2 years of age, and the highest incidence of 13.3% could be calculated for the period between 18 months and 2 years of age. There were no confirmed additional cases for children between 4 and 11 years of age. Infection with H. pylori thus occurs at an early age in a developed country (as well as in developing countries), and spontaneous clearance seems to be common.

Cerebrospinal fluid of newborn infants contains a deglycosylated form of the intermediate filament nestin

Nestin is an intermediate filament protein found in CNS progenitor cells. Nestin reappears in CNS tumor cells and reactive astrocytes after CNS injury. In this study we investigated whether nestin could be detected in the cerebrospinal fluid (CSF) of newborn infants and whether expression levels change with gestational age (GA) and/or brain injury. Using Western blot analysis, we examined the expression of nestin in the CSF of newborn infants (GA 25-42 wk) with asphyxia (n = 14), periventricular leukomalacia and peri(intra)ventricular hemorrhage (n = 7), and in a control group (n = 11). Protein extract from the periventricular brain tissue of a 1-wk-old infant was also analyzed. Nestin was detected in all the CSF samples and in the protein extract from the periventricular brain tissue. Although the CSF levels of nestin expression did not change with increasing GA, the asphyxia group had significantly lower levels of nestin in the CSF. An unexpected finding was that brain-derived nestin had an apparent molecular mass of approximately 240 kD, whereas all analyzed CSF samples contained two nestin-immunoreactive proteins at 200 and 220 kD. Experimental deglycosylation of the 240-kD form reduced the molecular mass to 220 kD, indicating that nestin undergoes a specific deglycosylation upon release into the CSF.

Concentrations of magnesium and ionized calcium in umbilical cord blood in distressed term newborn infants with hypoxic-ischemic encephalopathy

Magnesium and ionized calcium in mixed umbilical cord blood was assessed colorimetrically in 38 distressed and 21 healthy term newborn infants. Distressed infants with a severe or moderate degree of hypoxic-ischemic encephalopathy (HIE) (n = 8) had significantly lower (p < 0.001) concentrations of magnesium (0.52 +/- 0.08 mmol/L) compared to the control group (0.69 +/- 0.06 mmol/L). No differences in concentrations of ionized calcium between distressed and control infants were detected.

Enhanced expression of interleukin (IL)-1 and IL-6 messenger RNA and bioactive protein after hypoxia-ischemia in neonatal rats

The effect of hypoxia-ischemia (HI) on IL-1, and IL-6 bioactivity in relation to expression of IL-1 alpha, IL-1 beta, and IL-6 mRNA was studied, and the neuroprotective efficacy of IL-1 receptor antagonist (IL-1ra) was evaluated in neonatal rats. HI was induced in 7-d-old rats by unilateral carotid artery ligation and hypoxia for 70-100 min. Animals were killed at different time points up to 14 d after HI, and brains were analyzed for IL-1 and IL-6 bioactivity using bioassays and for mRNA for IL-1 alpha, IL-1 beta, and IL-6 with reverse transcription followed by a polymerase chain reaction. In separate animals, IL-1ra was administered intracerebrally before or after HI, and the extent of brain injury was assessed 14 d after HI. A transient increase of IL-1 bioactivity occurred after HI, reaching a peak at 6 h of recovery. IL-1 beta mRNA followed a similar time course but attained maximum expression at 3 h. IL-6 bioactivity and mRNA were also stimulated by HI and followed a similar time course as IL-1. Pretreatment with IL-1ra reduced HI brain damage from 54.4 +/- 9.3 to 41.4 +/- 10.0% (p < or = 0.01), and IL-1ra posttreatment increased the proportion of animals devoid of brain injury (40%) compared with vehicle-treated controls (13%) (p < or = 0.05). In conclusion, a transient activation of IL-1 and IL-6 occurred after HI, and IL-1ra reduced HI brain injury to a moderate degree.

Glial fibrillary acidic protein is increased in the cerebrospinal fluid of preterm infants with abnormal neurological findings

Glial fibrillary acidic protein (GFAP) is the structural protein of the intermediate filament of astroglia. The aims of the present study were to examine GFAP in the cerebrospinal fluid (CSF) of preterm infants at different postmenstrual ages and to evaluate the potential of GFAP to predict abnormal neurodevelopmental outcome. GFAP increased in correlation with postmenstrual age in preterm infants (n = 17) and full-term infants (n = 9). The levels were five times higher in preterm infants (n = 10) with an abnormal neonatal course and/or an abnormal neurological outcome than in healthy preterm infants. The positive predictive value of a GFAP higher than the 98th percentile of normal infants was 69%, while a GFAP level below this limit invariable predicted a good outcome. Simultaneously analysed noradrenaline, hypoxanthine and glutamate did not differ between the groups. We conclude that CSF GFAP increases with maturity and that CSF GFAP appears to be a promising marker for perinatal brain damage.

Early [18F]FDG positron emission tomography in infants with hypoxic-ischaemic encephalopathy shows hypermetabolism during the postasphyctic period

Six full-term infants suffering from perinatal asphyxia and with moderate or severe hypoxic-ischaemic encephalopathy were investigated by positron emission tomography (PET). Regional cerebral metabolic rates of glucose (rCMRgl) were determined using [2-18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG) PET scans at a median age of 2.5 days (range 2-5 days). Localized increases in rCMRgl were visually observed in five infants. In a subgroup of three infants, absolute values of rCMRgl in different brain regions were calculated. In all cases the results of the PET studies were in good agreement with those of the neuroradiological, neurophysiological and clinical investigations. Information indicating pathophysiological events could be extracted earlier with PET than with conventional morphological imaging techniques. We conclude that [18F]FDG-PET scans performed in critically ill, asphyxiated infants very soon after birth provide valuable information for the prediction about neurological outcome.

Acute effects of two different doses of magnesium sulphate in infants with birth asphyxia

The effects of two different doses of magnesium sulphate (MgSO4) were evaluated in a group of 15 full term infants with Apgar scores of < 6 at 10 minutes, studied within 12 hours of delivery. Seven infants received 400 mg/kg MgSO4 and eight received 250 mg/kg. After the larger dose, mean arterial pressure (MAP) fell by a mean of 6 mm Hg (13%) at one hour but was not significantly reduced thereafter. Respiratory depression lasted three to six hours. EEG readings and heart rate were not significantly different. Mean serum Mg2+ increased from 0.79 to 3.6 mmol/l at one hour. After 250 mg/kg MgSO4, MAP, EEG, tone and heart rate were unchanged. One infant developed transient respiratory depression. Mean serum Mg2+ rose from 0.71 to 2.42 mmol/l at one hour. MgSO4 (400 mg/kg) has an unacceptable risk of hypotension; 250 mg/kg MgSO4 was not associated with hypotension although respiratory depression can occur.

Glial fibrillary acidic protein in the cerebrospinal fluid: a possible indicator of prognosis in full-term asphyxiated newborn infants?

Glial fibrillary acidic protein (GFAP) is the structural protein of intermediate filaments in astroglia. GFAP has extensively been used as a marker of gliosis in neuropathology. It also appears in excessive amounts in the cerebrospinal fluid in various acute brain disorders. Hypoxic-ischemic encephalopathy after perinatal asphyxia is a condition in which levels of GFAP could be expected to be elevated if brain cell damage occurs. We examined levels of GFAP by a sensitive ELISA in the cerebrospinal fluid of full-term infants between 12 and 48 h after birth. Cerebrospinal fluid-GFAP increased 5-fold in infants after perinatal asphyxia compared with a reference group (675 versus 137 ng/L, p < 0.001). The levels of GFAP also increased gradually in accordance with the severity of the neurologic symptoms ranked as degree of hypoxic-ischemic encephalopathy. We conclude that the cerebrospinal fluid levels of GFAP might be an important adjunct in the neonatal assessment of infants subject to perinatal asphyxia, and together with other neuronal or glial proteins, it might also help in defining temporal relationships in asphyxia.

Monoamine neurotransmitters and metabolites in the cerebrospinal fluid following perinatal asphyxia

While the release of neurotransmitters is involved in the pathophysiology of brain damage following birth asphyxia, it also plays a role in endogenous defense against such damage. Levels of monoamines and the main cerebral monoamine metabolites in the cerebrospinal fluid (CSF) were measured in asphyxiated and control infants within 24 h after birth. The results indicate an increased turnover of noradrenaline (NA) and dopamine following asphyxia. Furthermore, the NA stores in the brain seem to be exhausted in some cases. We conclude that this increase in catecholamine turnover to some extent explains the clinical symptoms of hypoxic-ischemic encephalopathy and that it may reflect an intrinsic adaptive capacity to perinatal distress.

Adverse reactions after diphtheria-tetanus booster in 10-year-old schoolchildren in relation to the type of vaccine given for the primary vaccination

This prospective open study investigated adverse reactions in 527 schoolchildren to a diphtheria-tetanus (DT) booster given within a national vaccination programme at 10 years of age. Evaluation was based on those whose immunization records showed that they had received either three doses of an adsorbed DT vaccine (n = 388) or a non-adsorbed DT-pertussis vaccine (DTP) (n = 69) for primary series vaccination. No differences in systemic reactions to the booster between the two groups were observed. Local reactions were significantly (p < 0.001) more common 1 day after vaccination in children who had received DT for primary series vaccination: redness, 73% compared with 23%; swelling, 56% versus 15%; and itching, 47% versus 21%. One and 2 weeks after the booster, itching was still more pronounced in the group who had received DT for primary series vaccination (p < 0.001 and 0.014, respectively). The study indicates that there was a real basis for the increase in spontaneous notifications of local side-effects to the school DT booster in Sweden. The most likely cause for the increase seems to be the aluminium adjuvant in the vaccine given for primary vaccination, a late and unexpected consequence of a change in the infant immunization programme.

Excitatory amino acids in the cerebrospinal fluid of asphyxiated infants: relationship to hypoxic-ischemic encephalopathy

Asphyxiated (n = 27) and control infants (n = 25) were subjected to spinal taps. Amino acids were measured with liquid chromatography and the degree of hypoxic-ischemic encephalopathy was determined in each case. In asphyxiated infants, the concentrations of aspartate and glutamate were 286% and 387% (p < or = 0.01 and p < or = 0.05) of the control values, respectively. The cerebrospinal fluid aspartate levels were significantly (p < or = 0.05) higher in the group with severe (3.4 mumol/l) compared with the group with mild hypoxic-ischemic encephalopathy (1.0 mumol/l). Glutamate was also higher in the group with severe (12.3 mumol/l) than in the groups with mild (2.7 mumol/l) or moderate (3.2 mumol/l) hypoxic-ischemic encephalopathy (p < or = 0.05). High concentrations of excitatory amino acids were present in the CSF of asphyxiated infants which may exert excitotoxic effects.

Renal function in very low birth weight infants: normal maturity reached during early childhood

Development of glomerular and tubular renal function is delayed in preterm infants. To study the pattern of maturation during infancy and childhood, we re-evaluated renal function in 22 very low birth weight infants--in 14 of the infants at 18 months postconceptional age (9 months corrected age) and in the remaining 8 infants at 8 years of age. The glomerular filtration rate remained lower at 9 months corrected age than in term infants of the same postconceptional age: 82 +/- 23 versus 125 +/- 18 ml/min per 1.73 m2 (p < 0.001). At 8 years of age the glomerular filtration rate did not differ from that of healthy control subjects. Effective renal plasma flow, filtration fraction, albumin excretion, maximal concentrating ability, and kidney size determined by ultrasonography were all normal at 8 years of age. We conclude that renal function, which is markedly reduced during the neonatal period in very low birth weight infants, reaches normal maturity by 8 years of age but not by 9 months corrected age.

Long term serologic follow-up after pertussis immunization

Neutralizing antibodies to pertussis toxin (antitoxin) were determined in 201 blood samples from 4-year-old children. They had received primary immunization at 6 to 8 months of age with an acellular (n = 149) or a whole cell (n = 52) pertussis vaccine and 195 of them had received a booster dose of the acellular vaccine 9 to 16 months later. Data on exposure to pertussis and occurrence of pertussis were also collected. There was a rapid decrease of antitoxin between immediate postbooster titers and those measured 24 months later. This decrease per month was significantly greater than that after the primary immunization series (P less than 0.001). Neither the number nor the spacing of acellular vaccine doses given for primary series influenced the titers found 24 months after the booster. An antitoxin response was still measurable in 86% of the 196 four-year-old children. None of 19 exposed children developed whooping cough, which suggested that the antibody concentrations during the follow-up period were sufficient for protection. The results indicate a need for long term follow-up studies in the evaluation of new vaccines and immunization schedules.

Sixteen-month follow-up of antibodies to pertussis toxin after primary immunization with acellular or whole cell vaccine

Antibodies to pertussis toxin (antitoxin) were measured in three blood samples drawn during a 16- to 17-month follow-up of infants immunized with adsorbed two component acellular pertussis vaccine (JNIH-6) or plain whole cell vaccine. A significant decrease of antitoxin concentration was noted between each follow-up in the acellular vaccine groups (P less than 0.005). The higher antitoxin titers induced by three doses or by two doses spaced by 2 months compared with two doses with 1-month interval disappeared with time. The antitoxin titers among high responders to three doses of whole cell vaccine paralleled those of the acellular vaccinees but at a significantly lower level. Reported exposure to pertussis did not significantly alter the decrease of antitoxin titers. The study also showed that acellular pertussis vaccine induced an antitoxin response still measurable in greater than or equal to 97 and greater than or equal to 91% of samples drawn 10 to 11 and 16 to 17 months after primary immunization, respectively.