Download - Summer meeting of the Neonatal Society, 2004
Early Human Development 80 (2004) 169–192
www.elsevier.com/locate/earlhumdev
Abstract
Summer meeting of the Neonatal Society, 2004
1st–2nd July, 2004
St John’s College, Cambridge, UK
This meeting has been approved by the RCPCH for 7 CPD Credits
doi:10.1016/j.
Thursday 1st
12.00–13.35
13.35
Chair: Dr An
13.45
14.00
14.15
14.30
14.45
15.00
15.40
Chair: Dr Ho
16.00
earlhumdev.2004.07.002
July
Registration and lunch
Welcome
drew Lyon
Dr Mark Herbert, John Radcliffe Hospital
Group B Streptococcus gene expression in nutrient limited environments
Dr S Broughton, Kings College Hospital
Prospective study of risk factors for healthcare utilisation and RSV infection in prematurely
born infants
Dr A Thakor, University of Cambridge
The role of calcitonin gene related peptide (CGRP) in the umbilical vascular bed
Mr J Cockerill, Imperial College London
Breast milk attenuates poor postnatal growth in male preterm infants
Miss R Slater, University College London
Noxious Stimulation Causes Functional Activation of the Somatosensory Cortex in
Newborn Infants
Young Investigator Prize Lecture-Dr David Gardner
Fetal adaptation to the intrauterine environment: short and longer term consequences for
physiological development
Tea
ward Clark (Young Investigator Prize Winner 2001)
Dr A Lall, Hammersmith Hospital
T regulatory lymphocytes are found in fetal blood at 29 weeks gestation, but do not
express FOXP3
16.15 Dr F McCrosson, Royal Infirmary of Edinburgh
Changes in Body Temperature Immediately After Birth in Preterm Infants Resuscitated in
Polythene bags
16.30 Professor C Morley, Royal Women’s Hospital, Melbourne
Resuscitating very premature lambs with a Laerdal bag without PEEP or set tidal volumes
with PEEP: the effect on carbon dioxide and oxygenation
16.45 Dr E Johnson, University of Cambridge
Effect of maternal dexamethasone treatment on circulating and tissue angiotensin-converting
enzyme concentration in fetal sheep
Chairman: The President, Professor Andrew Wilkinson
17.00–18.00 The Tizard Lecture-Sir Iain Chalmers
Confronting therapeutic uncertainties in neonatal care
From 18.30 Drinks and Jazz band on lawn/patio
20.00 Conference Dinner/Entertainment (more music–bar–Cambridge walk–Punting)
Friday 2nd July
08.00–08.45 Breakfast
Chair: Dr Nicola Robertson
08.45 Dr L E Dyet, Hammersmith Hospital
Diffuse White Matter Abnormalities on Magnetic Resonance Imaging of the Brain in
Preterm Infants at Term and Neurodevelopmental Outcome
09.00 Dr K Thorngren-Jerneck, Lund University Hospital
Cerebral glucose metabolism measure by Positron Emission Tomography (PET) Magnetic
Resonance Imaging (MRI), diffusion weighted imaging (DWI) and 1H Spectroscopy in
term newborn infants with Hypoxic Ischemic Encephalopathy (HIE) after birth asphyxia
09.15 Dr O Iwata, University College London
Delayed hypothermia is neuroprotective in moderate, but not severe, perinatal
hypoxic-ischaemic injury
09.30 Dr N Kennea, Hammersmith Hospital
Functional Extrinsic and Intrinsic Apoptotic Pathways in Human Fetal Mesenchymal Stem Cells
09.45 Dr D Todd, Westmead Hospital, Australia
Retinopathy of prematurity in infants b30 weeks’ gestation in NSW and the ACT from
1992 to 2002
10.00 Dr L Dabydeen, University of Newcastle
Additional nutrition significantly increases brain growth in babies with perinatal brain damage
10.15 Keynote Lecture–Dr Robert Tasker
Hippocampal vulnerability, developmental amnesia, and what else?
11.00 Coffee
Abstract170
Chair: Dr Helen Budge (Young Investigator Prize Winner 2002)
11.20 Young Investigator Prize Lecture-Dr Karen Luyt
Metabotropic Neurotransmitter
Receptors in Oligodendrocytes: novel potential players in white matter development,
injury and repair
12.00 Dr M Gnanalingham, University Hospital Nottingham
Impact of delivery temperature on uncoupling protein-1 and -2 abundance on brown
adipose tissue in the newborn
12.15 Dr K L Franko, University of Cambridge
Effect of Maternal Protein Deprivation During
Pregnancy on Hepatic Gluconeogenic Enzyme in Rat Fetuses at Term
12.30 Keynote lecture-Dr Dino Giussani
Oxygen, fetal growth and cardiovascular development
13.15 Close of meeting and lunch
Our thanks in particular to Chiesi, and also to Draeger Medical, Fisher Paykel, S.L.E. and Vygon for
sponsoring this meeting.
Abstract 171
Noxious stimulation causes functional activation of the somatosensory cortex in
newborn infants
Rebeccah Slater1, Shiromi Gallella2, Stewart Boyd3, Judith Meek2, Maria Fitzgerald1
1Department of Anatomy and Developmental Biology, University College London,
London, UK2Department of Paediatrics, University College London Hospital, London, UK3Neurosciences Unit, Institute of Child Health, London, UK
Introduction: Noxious sensations can clearly stimulate the central nervous system,
producing reflex movements and a biochemical response, at a very early age
(Fitzgerald, 1999; Smith, 2000). The true experience of pain requires functional
maturation of higher brain centres, however, it is unclear at what CNS level this
response is produced. Here we report on the use of near infra red spectroscopy (NIRS)
to study the maturation of the cortical response to noxious sensation.
Aim: To use NIRS to investigate cortical pain processing in neonates using the
haemodynamic response in the somatosensory cortex to noxious stimulation.
Methods: Eleven preterm infants were studied during routine phlebotomy. All infants
had normal appearances on cranial ultrasound scans. The haemodynamic response to
the heel lance was measured using a double channel NIR spectrophotometer. The
optodes were positioned symmetrically on each side of the head over the
somatosensory cortex and changes in oxyhaemoglobin (HbO2), deoxyhaemoglobin
(HHb) and total haemoglobin (HbT) concentrations were measured.
Abstract172
Results: A haemodynamic response was successfully measured in seven infants with a
mean post menstrual age (pma) of 36.3 weeks. Four studies were excluded due to
motion artefact. Following the heel lance there was an increase in HbT in the
contralateral somatosensory cortex and a decrease in the ipsilateral somatosensory
cortex.
Postmenstrual
age (weeks)
Maximum change in contralateral HbT
(Amol/l) during 20 s following heel lance
Maximum change in ipsilateral HbT
(Amol/l) during 20 s following heel lance
29+5 8.67 �2.06
35+5 9.49 �6.05
30+0 1.53 �9.08
35+1 2.39 �0.56
37+5 3.11 �3.97
43+2 2.11 �12.98
42+0 10.62 0.63
Table showing maximum change in HbT in the contralateral and ipsilateral
somatosensory cortex following painful stimulation and a sample trace of the evoked
response in one infant.
Conclusion: Infants between 29 and 42 weeks pma show a large localised
somatosensory response to painful stimulation. The magnitude of the evoked responses
is similar to those obtained using visual and olfactory stimuli. This study shows that
noxious stimulation evokes neural activity in the somatosensory cortex at this age and
that both preterm and term infants are able to mount a cortical response to painful
stimuli.
References
Smith RP, Gitau R, Glover V, Fisk NM. 2000 Pain and stress in the human fetus. Eur J Obstet
Gynecol Reprod Biol. 92:161–5.
Fitzgerald M. 1999 The developmental neurobiology of pain. The textbook of pain, 4th edition. Ed
Wall PD and Melzack R, Churchill Livingstone, pp 235–252.
Abstract 173
Prospective study of risk factors for healthcare utilisation and RSV Infection in
prematurely born infants
Authors: Simon Broughton1, Alison Roberts1, Grenville Fox2, Mark Zuckerman3 and
Anne Greenough1
1Department of Child Health, Guy’s King’s and St Thomas’ Medical School, Kings
College Hospital, Denmark Hill, London SE5 9RS, UK2Department of Child Health, Guy’s, King’s and St Thomas’ Medical School, St
Thomas’ Hospital, Lambeth Palace Rd, London SE1 7EH, UK3Department of Microbiology, Guy’s King’s and St Thomas’ Medical School, Kings
College Hospital, Denmark Hill, London SE5 9RS, UK
Background: Prematurely born infants frequently require readmission or GP contacts
following NICU discharge, data from retrospective studies suggests this may be increased
following RSV infection.
Aims: In a prospective study to determine risk factors for healthcare utilisation and RSV
infection in babies born prematurely.
Methods: Babies born b32 weeks of gestation were recruited if they were born within
six months of the onset of the RSV season. Following discharge from the neonatal
unit, data were collected regarding subsequent healthcare utilisation; the number and
length of hospital admissions and GP consultations. The parents were asked to
contact a member of the research team if their baby had signs of a lower respiratory
tract infection (LRTI). In addition, all parents were contacted on a fortnightly basis
by the research team. If either contact indicated the baby had a LRTI, a member of
the research team visited the baby at home or at hospital and a nasopharyngeal
aspirate (NPA) was obtained. Healthcare utilisation and RSV infection were then
related to demographic, social and neonatal data to identify risk factors. Ethical
approval was obtained from the ethics committee and consent was obtained from the
parent.
Results: 119 babies (median gestational age 29, range 23–31 weeks) were recruited.
Eighty-six of the babies had signs of LRTI on 149 occasions and NPAs were
obtained. Thirty-eight (32% of 119) were RSV positive on 41 occasions. In addition
eight babies were positive for influenza and five for parainfluenza. Regression analysis
demonstrated that risk factors increasing for hospital admission were RSV infection
(odds ratio (OR) 3.21 (95% confidence intervals 1.29–8.01)) and parental smoking
(OR 3.59 (1.34–9.66)). Risk factors for hospital length of stay were gestation out of
oxygen ( pb0.001), parental smoking ( p=0.012) and RSV infection ( p=0.022).
Antenatal infection was protective ( p=0.049). The only risk factor identified for GP
consultations was RSV infection ( pb0.001). Risk factors identified for RSV infection
were smoking in pregnancy (OR 3.59(1.05–9.66)), being male (OR 2.62(1.05–6.50))
and the number of siblings (OR 1.65(1.12–2.14)) and antenatal infection was
protective (OR 0.35(0.12–0.97)).
Conclusion: RSV infection does increase healthcare utilisation in prematurely born infants.
These results further emphasise the need to counsel women against smoking during and
after pregnancy.
Abstract174
Corresponding Author: Prof. Anne Greenough.
Breast milk attenuates poor postnatal growth in male preterm infants
Jason Cockerill1, Ian de Vega2, Caroline Dore, Sabita Uthaya1 and Neena Modi1
1Imperial College London;2Hammersmith Hospitals Trust, London UK
Background: Extremely preterm birth is an acknowledged risk factor for poor growth.
Current clinical practice aims to promote postnatal weight gain and head growth. Male
infants are known to achieve less well than females over a range of outcomes, but there has
been little comparative evaluation of growth.
Aims: The aim of this study was to compare the pattern of weight gain and head growth to
age term-equivalent in male and female infants born V32 weeks gestational age (GA) and
to relate these to breast milk received and illness severity.
Methods: This study was approved by the hospital research ethics committee. We
extracted the following information from the Queen Charlotte’s and Chelsea Hospital
neonatal database on all inborn infants V32 weeks GA who remained in the neonatal unit
up to z37 weeks postmenstrual age and who had been admitted between 01/01/2002 and
31/12/2003: sex, head circumference (HC) and weight (Wt) at birth (B) and discharge (D),
date of birth and discharge, antenatal and postnatal steroid exposure, number of days any
breast milk was received and number of days receiving level 1 and 2 intensive care (3). We
expressed each anthropometric index as standard deviation score (SDS) and growth
between birth and 6 weeks as SDS gain (SDSG) calculated using commercially available
software based on the 1990 British growth reference. SDSG is the change in SDS adjusted
for sex and reference correlations between measurements at two time points. We expressed
days of level 1 and 2 intensive care (%L1 and 2IC) and the number of days breast milk
was received (%BM) as a percentage of the number of days from birth to discharge. Data
were analysed using SPSS version 11.5. Unless otherwise stated, data are presented as
mean (SD). The independent and paired samples t-test was used for between and within
group comparisons; equal variances were not assumed. Linear and multiple regression
analyses were used to compare weight and HC SDSG in male and female infants and to
investigate the interaction between %BM and sex.
Results: There were 29 boys and 32 girls. There was no significant difference between
boys and girls in GA, birth weight and HC, discharge HC, %BM or %L1 and 2IC
(table). No infant received postnatal steroids and all but 5 (4 boys, 1 girl) received
antenatal steroids.
GA
weeks
Bwt
Kg
BWt
SDS
BHC
cm
BHC
SDS
Dwt
Kg
DWt
SDS
DHC
Cm
DHC
SDS
Wt
SDSG
HC
SDSG
%BM %L1
and 2IC
Boys 29.0
(2.5)
1.22
(0.35)
�0.55
(0.91)
27.0
(2.07)
�0.35
(1.16)
2.59
(0.45)
�1.83
(0.98)
34.4
(1.7)
�0.37
(1.38)
�1.81
(1.08)
�0.02
(1.93)
81.6
(16.1)
37.2
(32.3)
Girls 28.6
(1.8)
1.14
(0.29)
�0.24
(0.99)
26.0
(2.2)
�0.56
(1.21)
2.68
(0.48)
�1.22
(0.94)
34.0
(3.3)
0.02
(2.81
�1.25
(0.81)
0.52
(3.53)
78.4
(23.5)
39.2
(27.8)
p 0.46 0.38 0.21 0.09 0.50 0.44 0.02 0.59 0.49 0.035 0.47 0.54 0.79
Abstract 175
There was a highly significant fall in weight SDS between birth and discharge
in both boys (mean difference 1.28, pb0.0001) and girls (mean difference 0.98,
pb0.0001). In contrast, head growth was maintained. No impact of %L1 and 2IC
on growth was identified. Though not significantly different between boys and
girls at birth, by discharge, boys had a significantly lower weight SDS and weight
SDSG was more negative (table). Multiple regression analysis, allowing for BWt
SDS, showed a significant positive relationship between weight SDSG and %BM
in the boys (B=0.031; p=0.01) but not the girls (B=�0.009; p=0.23). There was a
highly significant interaction between sex and %BM ( p=0.007). Based on the
mean BWt SDS for the whole group, and using the regression coefficients
obtained from the analysis of each sex separately, the mean difference between
boys and girls was 1.77 SDSG at 50%BM ( pb0.0001), reducing to�0.22 SDSG at
100%BM ( p=0.35).
Conclusion: Clinical management appears to have sustained postnatal head growth, in
contrast to weight gain, in this 2002/2003 cohort of extremely preterm infants. Postnatal
weight gain in boys is significantly worse than in girls but this difference is substantially
reduced by breast milk.
Additional nutrition significantly increases brain growth in babies with perinatal
brain damage
Dabydeen L, Thomas JE, Aston TJ, Hartley H, Sinha SK, Eyre JA
Developmental Neuroscience Group, School of Clinical Medical Sciences, University
of Newcastle upon Tyne UK NE1 4LP
Hypothesis: That increased nutrition during the first year in children with significant
perinatal brain damage will optimise growth.
Subjects: Babies with severe hypoxic-ischaemic encephalopathy, cystic periventricular
leucomalacia or intraventricular haemorrhage with parenchymal extensions, born in the
Northern Region.
Methods: The study was approved by the individual institution’s ethics committees. At
term subjects were randomly allocated into two groups, controlling for gestation, sex,
postcode and brain lesion. All were followed by a specialist dietician. The
intervention group had a dietary intake target of 120% of estimated energy
requirements and the control group, 100%. Anthropometric measurements and
transcranial magnetic stimulation to estimate maximum corticospinal axonal diameter
were performed at term and at three monthly intervals. Parents and researchers
collecting and analysing these measurements (LD and JAE) were blinded to patient
allocation.
Results: 16 babies were recruited over a 2-year period; 11 boys and 10 preterm infants.
There were no significant differences in sex, weight and head circumference centiles
between intervention and control groups at birth and at the start of the intervention (see
figure). The intervention group had significantly faster rates of weight gain in the first 6
months (Fig. A, pb0.05) and by 12 months were significantly longer (Fig. B, pb0.05), had
Abstract176
larger occipitofrontal circumferences (Fig. C, pb0.05) and greater corticospinal axonal
diameters than the control group (Fig. D, pb0.01).
Conclusion: This is the first randomised, double blind, prospective study of a nutritional
intervention in babies with significant perinatal brain damage. It demonstrates that
increased nutrition in the first year had a significant effect on the initial rate of weight gain
and on height, head circumference and maximum axonal diameter in the corticospinal
tract. These data also suggest that babies with significant perinatal brain damage may have
increased nutritional requirements to maintain normal rates of growth in the first 12
months after birth.
Figure legend: MeanF95%confidence limits (A) weight, (B) length, (C) head circum-
ference and (D) maximum corticospinal axonal diameter.
Stars—intervention; Hexagons—control.
Abstract 177
Acknowledgements: Newcastle Healthcare Charity, Wellcome Trust.
Diffuse white matter abnormalities on magnetic resonance imaging of the brain in
preterm infants at term and neurodevelopmental outcome
LE Dyet1, NL Kennea1, S Counsell2, P Duggan1, J Allsop2, E Maalouf1, MA
Rutherford2, AD Edwards1,2 and F Cowan1
1Department of Paediatrics and 2Imaging Sciences Department, MRC Clinical
Sciences Centre, Imperial College Faculty of Medicine, Hammersmith Hospital,
London, W12 0NN
Introduction: Diffuse Excessive High Signal Intensity (DEHSI) in the white matter on T2
weighted magnetic resonance (MR) imaging of the brain is present in approximately 75%
of preterm infants at term corrected age (1). MR diffusion imaging suggests that DEHSI
represents abnormality (2), and this is supported by its absence in normal term born
infants. It is therefore important to investigate whether DEHSI impacts on later
neurodevelopmental outcome.
Aim: To investigate the relationship between DEHSI on T2 weighted brain MR
imaging in preterm infants at term and their subsequent neurodevelopmental
outcome.
Methods: Infants were recruited from a consecutive cohort born at the Hammersmith
Hospital at b30 weeks gestation, who underwent serial brain MR imaging between
birth and term. The Hammersmith Hospitals Research Ethics Committee approved
the study. Infants with brain imaging at term and a neurodevelopmental assessment
at 2 years corrected age were eligible for this part of the study. Infants with focal
cerebral lesions known to be associated with a poor neurodevelopmental outcome
were excluded from further analysis; these included haemorrhagic parenchymal
infarction, cystic periventricular leucomalacia and cerebellar haemorrhage. The MR
images were analysed by two independent investigators and categorized as having
normal white matter, DEHSI or severe DEHSI on the basis of the degree of signal
abnormality. The Developmental Quotient (DQ) was calculated at 2 years corrected
age using Griffiths Mental Development Scales (Revised). The relationship between
DQ and DEHSI was analysed using Analysis of Variance with correction for
gestational age.
Results: 57 preterm infants were scanned at term and had a neurodevelopmental
assessment at 2 years corrected age. Eleven were excluded from further analysis
because of associated cerebral lesions. Thirty-four (74%) of the remaining infants had
DEHSI on their MR scan at term and six of these were classified as severe. There
was complete concordance between the two investigators for the classification of
DEHSI. The presence of DEHSI was not related to gestational age at birth ( p=0.7).
The mean (range) DQ in the 3 groups was 111 (91–154) for normal white matter, 94
(67–129) for DEHSI and 92 (84–106) for severe DEHSI. The presence and severity of
DEHSI was significantly related to a decreased DQ on neurodevelopmental assessment
( p=0.02).
Abstract178
Conclusion: The presence of DEHSI in the white matter on T2 weighted brain MR
imaging in the preterm infant at term is related to impaired neurodevelopmental outcome.
However, the aetiology and pathology underlying DEHSI remains unknown.
(1) Maalouf E et al., J Pediatr 1999; 135: 351–357.
(2) Counsell S et al., Pediatrics 2003; 112: 1–7.
Effect of maternal protein deprivation during pregnancy on hepatic gluconeogenic
enzyme in rat fetuses at term
K.L. Franko, S. Keele, A.J. Forhead and A.L. Fowden
Department of Physiology, University of Cambridge, Downing Street, Cambridge, CB2
3EG, UK
Background: In rats, protein deprivation during pregnancy alters hepatic glucose
handling in the adult offspring (1). In part, this is due to changes in the hepatic
activity of enzymes involved in glucose metabolism although the extent to which these
changes arise in utero or develop later in life remains unknown (1). In sheep, maternal
undernutrition during late gestation is known to increase gluconeogenic enzyme
activities in the fetal liver (2). This study examined the effect of feeding rats a low
protein (LP) diet throughout pregnancy on fetal hepatic activities of the key rate-
limiting enzymes in the glucogenic pathways, glucose-6-phosphatase (G6Pase) and
phosphoenolpyruvate carboxykinase (PEPCK).
Methods: Immediately after mating (0.5 days), female Wistar rats were fed ad libitum
with either normal chow (20% protein, n=7) or a low protein isocalorific diet (8%
protein, n=6) until 20.5 days of gestation (term 21 days) when their fetuses (LP,
n=93; Normal, n=88) were delivered for tissue collection under terminal anaesthesia.
After cerebral freezing, fetuses and placentae were weighed and fetal livers were
frozen in liquid nitrogen for determination of G6Pase and PEPCK activities as
described previously (3). Data is presented as mean (FSE) of the litter means for
each animal.
Results: Maternal protein deprivation significantly decreased fetal and placental weights
but significantly increased the fetal to placental weight ratio compared to normally fed
animals (Table 1). Fetuses of LP mothers also had significantly higher hepatic activities of
Table 1
Morphometry and hepatic gluconeogenic enzymes activities of rat fetuses from mothers on LP or normal diets
throughout pregnancy
Diet Weight Activity, U/g wet wt
Fetus, g Placenta, mg F:P ratio, g/g G6Pase PEPCK
Normal (n=7) 3.79F0.07 792F50 4.82F0.25 1.22F0.11 0.30F0.02
LP (n=6) 3.35F0.04* 574F22* 5.96F0.24* 1.76F0.14* 0.32F0.01
* Significantly different from values in the normal animals, pb0.02 (unpaired t-test).
Abstract 179
G6Pase, but not PEPCK, than those of normal mothers (Table 1). There was no significant
difference in hepatic protein content between fetuses of LP (91.6F2.7 mg/g, n=6) or
normal mothers (94.2F2.4 mg/g, n=7, pN0.05). Litter size did not vary significantly with
dietary treatment.
Conclusions: The results show that maternal protein deprivation increases placental
efficiency and the activity of G6Pase in fetal rat liver. Hence, the abnormalities in glucose
metabolism observed previously in the adult offspring of LP mothers may track from fetal
life.
(1) Ozanne, S (2001). BMB 60 143–152.
(2) Lemons, J. et al., (1986). Ped. Res. 20 676–679.
(3) Fowden, A.L. et al., (1993) J. Endo. 137 213–222.
Impact of delivery temperature on uncoupling protein-1 and -2 abundance on brown
adipose tissue in the newborn
M.G. Gnanalingham, L. Clarke1, A. Mostyn, M.E. Symonds and T.J. Stephenson
Centre for Reproduction and Early Life, Institute of Clinical Research, University
Hospital, Nottingham NG7 2UH
1Department of Agricultural Science, Imperial College London, Wye, Kent TN25 5AH
Introduction: The uncoupling proteins (UCP) are members of the inner mitochondrial
protein superfamily. The role of brown adipose tissue (BAT) UCP1 is clearly defined in
non-shivering thermogenesis by promoting proton re-entry in and bypassing ATP
synthase, while UCP2 has many postulated roles including thermogenesis, apoptosis
and immunity. We have previously shown that delivery temperature is a major factor in
brown adipose tissue function in the newborn (1). The extent to which delivery
temperature affects the abundance of UCP1 and UCP2 mRNA in BAT has not yet been
determined.
Methods: Eight triplet-bearing ewes were entered into the study. Four randomly selected
ewes were given a 16-mg dexamethasone (Dex) intramuscular injection at 138 days of
gestation, followed by Caesarean section delivery at 140 days gestation (termi147 days).
The four untreated ewes (Controls) were also delivered by Caesarean section, but at 146
days. One lamb from each ewe was humanely euthanased (100 mg kg�1 pentobarbital
sodium: Euthatal, i.v.) as a fetus to enable BAT dissection, while the remaining lambs were
delivered either into a warm (WD, 30 8C) or cool (CD, 15 8C) ambient temperature, with
tissue sampling at 6 h of life. Total BAT RNAwas extracted, reverse transcribed and UCP1
and 2 mRNA abundance measured by RT-PCR using oligonucleotide primers designed
specifically to ovine UCP1 and 2. The mRNA results are given as means and standard
errors (SEM) in arbitrary units, as a ratio of 18S rRNA and are expressed as a percentage
of a reference sample. Statistical differences between groups were analysed by one-way
ANOVA with post-hoc Bonferroni.
Abstract180
Results:
Fetal Control Warm Control Cold Control Fetal Dex Warm Dex Cold Dex
UCP1 mRNA mean 66.6 26.1* 74.3 69.3 53.6y 75.4
SEM 1.8 2.8 3.0 3.0 2.2 2.3
UCP2 mRNA mean 65.7 19.5* 45.5 40.8 34.0y 53.8
SEM 2.2 3.6 1.9 4.1 3.2 3.8
* pb0.001, difference between warm vs. fetal or cold controls.y pb0.05, warm vs. cold DEX.
WD resulted in decreased UCP1 and UCP2 mRNA abundance in BAT from control
groups. This effect was reduced with DEX treatment, resulting in WD groups having
higher UCP1 and UCP2 mRNA abundance than their untreated controls ( pb0.05). DEX
WD resulted in reduced time to restore colonic temperature compared to DEX CD (WD
70F7, CD 128F22 min, pb0.05).
Conclusion: Delivery temperature is a major factor determining UCP1 and UCP2 mRNA
abundance in neonatal BAT. The potentially reduced thermogenic capacity of BAT with
WD may be blunted by antenatal DEX treatment, a response that is associated with
improved thermoregulation.
(1) Clarke L, Heasman L, Firth K and Symonds ME. Am J Physiol 1997; 272:
R1931-39.
Group B Streptococcus gene expression in nutrient limited environments
Mark Herbert, Catty Beveridge, Lori Synder, Nigel Saunders
Neonatal Unit, Department of Paediatrics, University of Oxford, John Radcliffe
Hospital, Oxford, UK
Purpose: We aimed to study gene expression in Group B Streptococcus (GBS) when
grown in nutritionally deplete environments, such as amniotic fluid. Our long-term goal is
to identify key regulators of virulence that can be targeted to develop novel means of
preventing Early-Onset Sepsis (EOS).
Experimental design: We developed a 384-probe sub-microarray containing probes to all
the known GBS regulator, virulence and transporter genes, and genes involved in
adaptation to reactive oxygen intermediate stress. RNAwas extracted from GBS grown in
amniotic fluid and rich media (Todd Hewitt Broth; THB). RNA profiles were stabilised
with RNAlater. RNAwas converted to cDNA, indirectly labelled with Cy3 and Cy5 dyes,
hybridised to the sub-array in Genetix hybridisation solution at 658C for 8 h, and washed
with Genetix wash solutions. The hybridised arrays were read on a Genepix 4000B
microarray scanner.
Results: The gene expression of GBS grown in THB was compared at mid- and late-
logarithmic and early-stationary phases (figure). Comparisons between genes expressed in
THB and amniotic fluid is on going.
Abstract 181
Figure legend: Gene expression at 3 compared with 5 h growth in THB. Blank spots
represent no detectable gene expression, bright yellow spots indicate genes that are
strongly expressed under both conditions, and red or green spots indicate genes up or
down regulated, respectively, at 3 compared with 5 h.
Identifying the genes that are essential for growth during nutritional depletion
(such as late logarithmic phase growth in THB and in amniotic fluid) may reveal an
Achilles heel that can be targeted to inhibit GBS growth during the initiation of EOS.
Three regulators of virulence, encoded by mga, rofA and nra, were shown to be up
or down regulated according to bacterial density and nutrient availability. Also as
GBS reaches late logarithmic growth virulence genes encoding C5a peptidase, sialic
acid synthesis genes and hemolysin are up regulated, as are peptide, sugar and
phosphate transporters, and enzymes excreted to damage host cells in the immediate
environment and thus release nutrients. Parallel experiments in amniotic fluid are
underway.
Conclusions: We have identified regulators of virulence of GBS that are expressed
during nutritional depletion in vitro. If these same genes are expressed during growth
in amniotic fluid, then these can be targeted for the development of inhibitors to
prevent GBS EOS.
Delayed hypothermia is neuroprotective in moderate, but not severe, perinatal
hypoxic-ischaemic injury
O Iwata, E DeVita, J Thornton, F O’Brien, S Iwata, Shanmugalingam S, D Peebles,
F Scaravilli, E Cady, R Ordidge, JS Wyatt, NJ Robertson
Departments of Paediatrics and Child Health, Medical Physics and Bioengineering,
University College London, London WC1E 6JJ
Background: Increasing evidence suggests that mild to moderate hypothermia is
neuroprotective when commenced shortly after a hypoxic-ischaemic (HI) insult
(Sirimanne et al., 1996). The extent of the neuroprotection, however, may be dependent
on the delay, duration and depth of hypothermia and on the severity of the HI injury. A
precise definition of the patient group who will respond to neuroprotective intervention is
urgently required.
Abstract182
Objective: To assess the relationship between the severity of the HI insult and the
efficacy of hypothermic neuroprotection assessed histologically in an experimental
model.
Design/Methods: 19 piglets were anaesthetised within 24 h of birth using isofluorane
and morphine, mechanically ventilated and randomised to three groups; (i)
normothermic (n-HI, n=6); (ii) core temperature 35 8C (35-HI n=6); and (iii) core
temperature 33 8C (33-HI n=7). Animals were then subjected to a transient HI insult
(bilateral carotid occlusion and FiO2 12–16% forc1 h). Phosphorus magnetic
resonance spectroscopy gave a measure of the duration and magnitude of acute
depletion of nucleotide triphosphate (NTP) relative to the exchangeable high energy
phosphate pool (EPP): Animals were subgrouped into: (i) moderate insult (n-HI-m, 35-
HI-m, 33-HI-m); and (ii) severe insult (n-HI-s, 35-HI-s, 33-HI-s). Animals were
maintained at target temperature for 24 h commencing 2 h after the end of the insult
and then rendered normothermic. At 48 h the animal was sacrificed and the brain
perfusion fixed. Hematoxylin and eosin stained slices were assessed in 10 regions in
the cortex and six regions in the deep grey matter. Percentages of viable and necrotic
neurons in each region were compared in subgroups.
Results: Consolidating all grades of HI insult, compared to the n-HI group, 33-HI and 35-
HI animals both had less dead neurons; only the 33-HI group had more viable neurons
(Fig. 1, all pb0.05). In the normothermic group histological scores were similar in
moderate and severe insults (Fig. 2). Hypothermic intervention improved histological
scores in the moderate insult groups (35-HI-m, 33-HI-m) but not in the severe insult
groups (Fig. 2).
Abstract 183
Conclusion: These data suggest that HI insult severity affects the efficacy of subsequent
hypothermic intervention; systemic hypothermia of 35 and 338C were neuroprotective
only after moderate HI insults.
Reference
Sirimanne ES, Blumberg RM, Bossano D et al., The effect of prolonged modification of cerebral
temperature on outcome after hypoxic-ischaemic brain injury in the infant rat. Pediatr Res 1996;
39:591–7.
Effect of maternal dexamethasone treatment on circulating and tissue angiotensin-
converting enzyme concentration in fetal sheep
Johnson E, Giussani DA, Fowden AL and Forhead AJ
Department of Physiology, University of Cambridge, Downing Street, Cambridge CB2
3EG, UK
Introduction: Angiotensin-converting enzyme (ACE) catalyses the production of
angiotensin II and the degradation of bradykinin. In adult life, the enzyme is primarily
found in the pulmonary vasculature. However, in the fetus, pulmonary blood flow is
relatively low, and the placenta is an alterative site of ACE activity. In preparation for
birth, ACE content in the fetal circulation, lungs and kidneys increases towards term in
association with the prepartum rises in cortisol and triiodothyronine (T3). Intravenous
infusion of cortisol, dexamethasone (DEX) or T3 to the sheep fetus has been shown to
elevate pulmonary, but not renal, ACE concentration. This study investigated the effect of
maternal DEX treatment, in clinically relevant doses, on circulating and tissue ACE
concentrations in fetal sheep.
Methods: From 125 days of gestation (term 145F2 days), 10 ewes carrying single
fetuses were injected twice i.m. with either saline (0.9% NaCl, n=5) or DEX (2�12
mg in 2 ml 0.9% NaCl, n=5) at 24 h intervals. Ten hours after the second injection,
the ewes and fetuses were euthanised, and umbilical arterial blood, lungs and kidneys
were collected. Plasma and tissue ACE concentrations were measured by a
spectrophotometric enzyme assay, and plasma cortisol, T3 and thyroxine (T4) were
determined by radioimmunoassay. Data (meanFSEM) were analysed by unpaired t-test
and linear regression.
Results: In the DEX-exposed fetuses, plasma cortisol was significantly lower (8.6F0.7
vs. 16.1F2.8 ng ml�1, pb0.05) and plasma T3 was significantly higher (0.77F0.05 vs.
0.28F0.06 ng ml�1, pb0.001) than in the control fetuses. Plasma T4 concentration was
similar in the two groups of fetuses (saline 132.5F11.7 vs. DEX 126.3F22.0 ng
ml�1). Maternal DEX treatment caused significant increments in both plasma and
pulmonary ACE concentration in the sheep fetus (Fig. 1, pb0.05). No significant
difference in renal ACE was seen between the saline and DEX-exposed fetuses (saline
Abstract184
1.54F0.08 vs. DEX 1.78F0.31 nmol min�1 mg protein�1). When values from all
fetuses were considered, significant correlations were observed between plasma T3 and
ACE in both the plasma (r=0.63, pb0.05, n=10) and lungs (r=0.82, pb0.005, n=10).
Conclusions: Maternal DEX treatment increases circulating and pulmonary ACE
concentrations in the sheep fetus. These findings have implications for glucocorticoid-
induced maturation of the fetal renin-angiotensin system, and the control of cardiovascular
and renal function over the perinatal period.
Supported by the BBSRC and Tommy’s, the baby charity.
Functional extrinsic and intrinsic apoptotic pathways in human fetal mesenchymal
stem cells
Nigel Kennea, Christina Stratou, Andreas Naparus, David Edwards and Huseyin
Mehmet
Department of Paediatrics, Imperial College Faculty of Medicine, Hammersmith
Hospital, Du Cane Road, London, UK
Background: While stem cells offer significant promise for the correction of neuro-
degenerative diseases and acute brain injury, a major obstacle is the poor survival of
grafted cells, the majority of which die by apoptosis. We have recently identified a
population of human fetal mesenchymal stem cells (FMSC)1 that can be differentiated into
neural cells both in vitro and in vivo. If cell replacement therapy with FMSC is to be
considered for brain injury, knowledge of the cell death machinery is essential to develop
strategies to prevent graft loss. Currently, nothing is known about the mechanisms by
which FMSC undergo cell death.
Abstract 185
Objective: To determine whether human FMSCs have functional apoptotic machinery
in both the intrinsic (mitochondrial) and extrinsic (death receptor) pathways and to
investigate whether stem cell survival can be prolonged by inhibition of death
signalling.
Design/Methods: We investigated apoptosis in FMSCs subjected to three different death
stimuli: serum withdrawal, Fas ligation or treatment with staurosporine (SSP). We studied
the components of the classical mitochondrial and death receptor pathways. Apoptosis was
defined using morphological and biochemical methods. Cytochrome c localisation was
determined by immunofluorescence, and activation of caspases using cleavage specific
antibodies. DNA fragmentation was confirmed by TUNEL.
Results: Activation of the mitochondrial pathway by SSPwas demonstrated by the release of
cytochrome c from mitochondria and subsequent cleavage of caspases 9 and 3 followed by
DNA fragmentation indicated by TUNEL labelling of apoptotic nuclei. Serum withdrawal
resulted in a similar pattern of molecular events, although the time course was significantly
longer. In addition, the PKB/Akt pathway was down-regulated in serum-starved MSC
cultures. Caspase 9 inhibitors, and the pan-caspase inhibitor z-VAD.fmk attenuated
apoptosis triggered by SSP treatment. Death receptor machinery was present in FMSCs
and was demonstrated to be functional by the rapid induction of apoptotic death by Fas
ligand. This effect was attenuated by the selective caspase-8 inhibitor IETD.fmk as well pan-
caspase inhibitors.
Conclusions: These results demonstrate intact intrinsic and extrinsic apoptotic pathways in
FMSC, and thus provide insights into potential mechanisms of human FMSC apoptosis
following transplantation. This may be useful in the design of pharmacological agents to
prolong the survival of stem cell grafts.
Reference
(1) Campagnoli, C. et al. Identification of mesenchymal stem/progenitor cells in human first-
trimester fetal blood, liver, and bone marrow. Blood 98, 2396-2402 (2001).
Tregulatory lymphocytes are found in fetal blood at 29 weeks gestation, but do not
express FOXP3
A Lall1,2, J Yates2, P Duggan1,2, N Kennea1 , M Butler2, G Lombardi2, R Lechler2, AD
Edwards1,3
1Department of Paediatrics, 2Department of Immunology and 3MRC Clinical Sciences
Centre, Imperial College Faculty of Medicine, Hammersmith Hospital, Du Cane Road,
London, UK
Introduction: In recent years, regulatory T (Treg) lymphocytes that constitutively express
CD4 and the Interleukin-2 receptor-a chain (CD25) have been shown to modulate the
inflammatory response to infection and prevent autoimmune disease. In mice the Treg
subset appears only in postnatal life; however we have previously described a similar
population of Treg cells in healthy, term, newborn infants (1) and suggested that these cells
may play a role in the control of inflammation in the fetal and perinatal period.
Abstract186
Expression of the FOXP3 gene has to date been found universally in rodent and human
Treg cells and it is suggested that FOXP3 confers these cells with regulatory properties.
Aim: The aim of this study was to investigate whether Treg cells exist in the human fetus and
to determine whether their phenotype and function was similar to that found in healthy
newborn infants and adults. In particular we askedwhether FOXP3was expressed in this cell
population.
Methods: Umbilical cord blood was obtained from three preterm infants who were delivered
by caesarean section without labour or rupture of membranes, median gestational age 30
(range 29–32) weeks. Bloodwas also obtained from the umbilical cords of three healthy full-
term infants, who were delivered by an elective caesarean section following a normal
pregnancy and peripheral blood samples were obtained from healthy adult volunteers.
Mononuclear cells (MCs) were obtained by density centrifugation using lymphoprep
(Nygaard). Non-CD4+ cells were depleted by negative selection and CD4+CD25+ cells were
then isolated by positive selection using CD25+ magnetic beads (Dynal) at 4 8C. IsolatedCD4+ cells were stained at a concentration of 104 cells in 100 ul of 1% PBS for 20–30 min at
4 8C in the dark with a range of antibodies and their surface phenotype assessed by flow
cytometry. CD3CD28 beads (Dynal) were used as stimulators in proliferation assays (in
vitro) with incorporation of 3H thymidine as the readout. RNA was extracted from
CD4+CD25+ and CD4+CD25� cells, quantified and then incubated with reverse
transcriptase to generate cDNA. FOXP3-specific primers were then used in the PCR
reaction and the samples run on a 1% TAE gel and photographed under UV light.
Results: All term and preterm infants had Treg cells isolated from umbilical cord blood.
These cells demonstrated typical T regulatory properties, being both hyporesponsive to
stimuli and suppressing proliferation of T effector cells in co-culture. However mRNA for
FOXP3 was only detected in term infants.
Conclusions: These results demonstrate that fully functional Treg cells arise in humans by
29 weeks gestation age. FOXP3 is not involved in the regulatory mechanisms of these
cells in preterm infants and thus is not essential for regulatory function in humans.
Reference
(1) Ng WF, Duggan PJ et al. (2001). Human CD4(+)CD25(+) cells: a naturally occurring population
of regulatory T cells. Blood 98(9): 2736–44.
Changes in body temperature immediately after birth in preterm infants resuscitated
in polythene bags
Fiona McCrosson, David Quine, Claire L Smith, Lawrence Armstrong, Andy
Lyon, Ben Stenson
Simpson Centre for Reproductive Health, Royal Infirmary of Edinburgh, 51 Little
France Crescent, Edinburgh EH16 4SA, UK
Background: Low admission temperature is an independent risk factor for death in
preterm infants (1). The use of polythene bags during resuscitation enhances thermal
Abstract 187
stability (2), but concerns have been raised that it may induce potentially damaging
hyperthermia (3).
Aims: To measure the changes in body temperature immediately after birth in infants b29
weeks gestation who were resuscitated in polythene bags and to quantify the extent of any
associated iatrogenic hyperthermia.
Methods: In a prospective study, infants b29 weeks gestation were laid on a temperature
probe within a polythene bag immediately after birth and were then resuscitated under a
radiant heater set to maximum. Sub-scapular temperature was documented every minute
during the first 15 min of life.
Results: In an 8-month period to May 2004, 27 infants (14 males, 13 females) were
studied. The mean (range) gestation and birth weight were 26+4 weeks (24–28+5) and 916
g (490–1470). The mean (range) temperature at 15 min was 37.3 8C (36.3–38.1). No infant
became hypothermic. 16/27 infants had temperatures that never exceeded 37.5 8C. 8/27(30%) infants had initial temperatures above 37.5 8C: five of them cooled gradually during
resuscitation towards 37 8C, the remaining three warmed by 0.2, 0.3 and 0.4 8C to a
maximum of 38 8C. 3/27 infants with normal initial temperatures warmed during
stabilisation to temperatures above 37.5 8C. The increases in temperature were 0.2, 0.6 and
0.6 8C and the maximum temperature reached was 38.1 8C. One of these three infants diedat 6hrs of age from proven group B streptococcal disease.
Conclusions: The use of polythene bags can eliminate hypothermia during resuscitation in
preterm infants. A significant proportion of babies (30%) have a high temperature before
stabilisation. Iatrogenic temperature increases during resuscitation occur in a minority of
infants and are small. The maximum iatrogenic increase in temperature was 0.6 8C.
References
(1) Costeloe K, Hennessy E, Gibson AT, et al. The EPICure study: outcomes to discharge from
hospital for infants born at the threshold of viability. Pediatrics 2000;196: 659–71.
(2) A J Lyon and B Stenson. Cold comfort for babies. Arch. Dis. Child. Fetal Neonatal Ed., Jan
2004; 89: F93.
(3) T Newton and M Watkinson. Preventing hypothermia at birth in preterm babies: at a cost of
overheating some? Arch. Dis. Child. Fetal Neonatal Ed., May 2003; 88: F-a256.
Resuscitating very premature lambs with a Laerdal bag without PEEP or set tidal
volumes with PEEP: the effect on carbon dioxide and oxygenation
Morley CJ, Probyn M, Hooper S, Dargaville P, McCallion N, Harding R
Department Physiology, Monash University, Melbourne, Australia
Royal Children’s Hospital, Melbourne, Australia
Royal Women’s Hospital, Melbourne, Australia
Background: Hypocarbia during neonatal ventilation has been associated with neonatal
chronic lung disease and adverse neurodevelopmental outcomes. It has been suggested
hypocarbia may occur during resuscitation. Very immature surfactant deficient lungs
Abstract188
collapse easily after expansion. PEEP is used during neonatal ventilation to reduce
expiratory lung collapse but it is not recommended during resuscitation.
Aim: To investigate the effect on carbon dioxide and oxygenation of resuscitating very
premature lambs with different tidal volumes and end expiratory pressures.
Methods: Anaesthetised lambs delivered at 126 days gestation were randomised to 15 min
resuscitation with three regimes: (1) Laerdal resuscitation bag (BR) with 100% oxygen and
no PEEP, (2) tidal volume (VT) of 5 ml/kg (VG5), or (3) VT of 10 ml/kg (VG10) delivered
with a Babylog 8000 ventilator in volume guarantee mode. Groups (2) and (3) received 8 cm
H2O PEEP and variable FiO2. Blood gases were measured every 5 min and VT, mean airway
pressure, minute volume, ventilation rate, respiratory system compliance and alveolar/
arterial oxygen difference (AaDO2) were recorded or calculated.
Results: Twenty intubated lambs were studied during resuscitation. BR (1) was associated
with more variable VT and peak inspiratory pressures compared to volume guarantee
ventilation (groups 2 and 3). The lambs ventilated from birth with a tidal volume of 10 ml/kg
were hypocarbic; and those ventilated at 5 ml/kg were hypercarbic. Lambs resuscitated with
the Laerdal bag had a mean VT of 7.5 mL/kg and were normocarbic. The two set tidal
volumes had little effect on oxygenation. The set tidal volume groups had PEEP and their
improved oxygenation compared with the Laerdal bag without PEEP. The coefficient of
variation of the VT was greatest with bagging (31.4F2.7%) compared to the 5 ml/kg group
(6.5F0.3%) and 10 ml/kg group (5.5F0.5%) ( pb0.001). The Table shows the values at 15
min expressed as mean and SEM.
Values at 15 min after birth (1) Bag resuscitation
without PEEP
(2) Set VT 5 ml/kg
with PEEP
(3) Set VT 10 ml/kg
with PEEP
Tidal volume (ml/kg) 7.4F0.6 4.9F0.1 9.4F0.03
PaCO2 (mm Hg) 49.9F2.9 64.1F5.6y 27.9F2.3*
pH 7.23F0.03 7.19F0.03 7.42F0.04
Minute volume (ml/kg/min) 449F36 435F23 467F42
AaDO2 480F42** 255F81 241F64
Peak inspiratory pressure (mm Hg) 39.2F2.4 34.3F1.6 46.4F3.9
Mean airway pressure (mm Hg) 13.1F0.8 16.5F0.6 20.4F1.0
* pb0.05 for VG10 vs. BR and VG5.
** pb0.05 for BR vs. the others.
y pb0.05 VG5 vs. BR.
Conclusion: Very premature lambs can be effectively resuscitated from birth using a set
tidal volume and volume guarantee ventilation. Within minutes of birth different tidal
volumes had a large effect on PaCO2. The use of PEEP halved the oxygen requirement in
15 min. Studies are needed to determine the tidal volume and PEEP for resuscitating very
premature infants to obtain acceptable levels of PaCO2 and oxygenation.
The role of calcitonin gene related peptide (CGRP) in the umbilical vascualr bed
A.S. Thakor and D.A. Giussani (introduced by Alison Forhead)
Department of Physiology, University of Cambridge, Cambridge CB2 3EG, UK
Abstract 189
Introduction: There has been a long-standing clinical and physiological interest in
haemodynamic changes in the umbilical vascular bed during pregnancy, due to its
functional importance in representing feto-placental blood flow and, hence, fetal well-being.
Novel and potent vasodilator peptides, like CGRP, are rapidly gaining interest in
cardiovascular regulation in the adult. However, its role in fetal cardiovascular function is
largely unknown. This study tested the hypothesis that CGRP has a vasodilator role in the
umbilical vascular bed during basal and hypoxaemic conditions in late gestation.
Methods: Under halothane anaesthesia, five sheep fetuses were instrumented with catheters
and a Transonic flow probe around an umbilical artery, inside the fetal abdomen, at 0.8 of
gestation. Five days later, animals were subjected to a 2.5-h protocol: 1 h normoxia, 0.5 h
hypoxaemia and 1 h recovery, during either saline i.v. or fetal treatment with a CGRP
antagonist (50 ıg kg�1 i.a. bolus+10 ıg kg�1.min�1 i.v. infusion). Hypoxaemia during saline
or antagonist treatment occurred on separate days in a randomised order. Antagonist
treatment started 30 min before hypoxaemia and ran continuously until the end of the
challenge. Two days later, all fetuses also received 2 and 5 ıg bolus doses of exogenous
CGRP i.a. Both doses were then repeated after the NO clamp, a technique that permits
blockade of de novo synthesis of NOwhile compensating for the tonic production of the gas,
therebymaintaining basal cardiovascular function (Gardner andGiussani.Circulation 2003,
108:331–5). Umbilical vascular conductance (UVC) was calculated by dividing umbilical
blood flow (UBF) by supra-amniotic fetal arterial blood pressure (BP).
Results: Fetal treatment with the CGRP antagonist did not alter basal blood gas status or
basal cardiovascular variables. A similar fall in PaO2 occurred in fetuses during either
saline (21+0.8 to 9+0.9) or antagonist treatment (20+0.9 to 9+1.2 mm Hg). Acute
hypoxaemia during saline infusion led to significant increases in BP (64+1.3 to 81+2.6
mm Hg), UBF (134+10 to 196+16 ml min�1) and UVC (2.1+0.2 to 2.7+0.3 (ml min�1)
mm Hg�1). In marked contrast, acute hypoxaemia during fetal treatment with the CGRP
antagonist led to pronounced falls in both UBF (140+13 to 90+10 ml min�1) and UVC
(Fig.1A) without affecting the magnitude of the hypertensive response. Exogenous
treatment of the fetuses with 2 and 5 ıg of CGRP during saline produced similar increases
in UVC. Remarkably, this vasodilator effect of CGRP was reversed to constriction
following NO blockade (Fig. 1B).
Abstract190
Conclusion: Combined, the results support the hypothesis and suggest an important role
for CGRP in pregnancy, maintaining UBF via NO-dependent mechanisms during basal
and hypoxaemic conditions.
Supported by The Journal of Experimental Pathology and The Lister Institute for
Preventive Medicine.
Cerebral glucose metabolism measured by positron emission tomography (PET),
magnetic resonance imaging (MRI), diffusion weighted imaging (DWI) and 1H
spectroscopy (MRS) in term newborn infants with hypoxic ischemic encephalopathy
(HIE) after birth asphyxia
K. Thorngren-Jerneck1, I. Burtscher2, B. Geijer2, T. Ohlsson3, A. Sandell3, S.-E.
Strand3 and S. Holt3s2
Departments of Pediatrics1, Neuroradiology2 and Radiation Physics3 University
Hospital, Lund, Sweden
Background: Severe birth asphyxia in term newborn infants is an important cause of
cerebral palsy.
Aim: To investigate early changes in MRI, 1H-MRS, DWI in relation to cerebral metabolic
rate of glucose (CMRgl) measured by PET, and outcome in terms of cerebral palsy, in term
newborn infants with HIE after birth asphyxia.
Method: Six term infants (35–42 weeks) with HIE were studied with MRI, DWI and MRS
(1.5 T MR unit; patient in sedation) at a postnatal age of 1–5 days. MR spectra were
analysed for N-acetylaspartat (NAA), cholin, creatine and lactate. Four patients were
studied with 2-18FDG-PET (2-[18F]fluoro-2-deoxy-D-glucose-PET, Scanditronic PC 384-
7 PET-camera with a spatial resolution of 7 mm; no sedation) at postnatal age 7–11 days.
HIE was classified according to Sarnat (mild, moderate or severe).
Results: All infants had signs of perinatal distress (first artery pH 6.88–7.09; base excess
�25 to �16; low 5-min Apgar score (b4). Four infants developed moderate HIE and two
Abstract 191
severe HIE. Two infants with severe HIE died, two infants with moderate HIE developed
cerebral palsy, one infant is healthy at 18 months follow up and one infant at present age of
7 months is not yet conclusive concerning outcome. On conventional MRI (T1 and T2)
pathological signs were detectable at 1–5 days postnatal age in the ventral part of thalamus
and posterior part of putamen. Increased signal on DWI was detectable in the thalamus in
all infants with CP and both infants who died. In one infant with CP also parasagittal
cortical changes were detectable. All but one child with moderate HIE and CP showed
detectable lactate levels. Lactate levels were higher in cases with severe HIE compared to
those with moderate HIE. In the two cases with severe HIE, creatine levels were lower
compared to NAA levels than in cases with moderate HIE. All patients showed higher
choline/NAA ratios than normal controls presented in the literature. In all four infants
studied with PET, the most metabolically active brain areas were the deep subcortical
parts, thalamus and basal ganglia. In two infants with CP after moderate HIE, quantitative
values were measured with CMRglc 25.6 and 27.6 Amol/100 g/min, respectively.
Conclusion: This is the first study presenting MRI, DWI, MRS and CMRglc in infants
with HIE. MRI and DWI show pathologic alterations in patients with HIE. MRS might be
useful in the prediction of clinical outcome in infants with perinatal asphyxia based on
detectable lactate levels, decreased total creatine and decreased NAA levels, in patients
with HIE. Infants who develop CP after HIE, have low cerebral glucose metabolism, when
measured in the subacute phase after perinatal asphyxia.
Retinopathy of prematurity in infants b30 weeks’ gestation in NSW and the ACT
from 1992–2002
Todd DA1, Wright A2, Byth K3, Smith J4 and the NICUS Network5
Clinical Fellow1, Clinical Nurse Educator2, Statistician3, Ophthalmologist4, NICU
Westmead Hospital, Westmead, Sydney, NSW Australia, 2145
NSW and ACT Neonatal Intensive Care Units Network5
Introduction: Retinopathy of Prematurity (ROP) still remains one of the main morbidities
for the preterm infant. We showed that in NSW from 1986 to 1992 there was an increased
incidence of ROP, but more recent data suggests that over the last few years the incidence
has decreased (1,2).
Aims: To study the incidence, severity and treatment of ROP in NSW and the ACT from
1992 to 2002.
Methods and materials: Prospective data from the NICUS Network Data Collection was
reviewed over an 11-year period to study ROP in infants b30 weeks’ gestation. The 11-year
period was divided into foru epoch’s to review the trend (Jan 92–Dec 94, Jan 95–Dec 97, Jan
98–Jun 00 and Jul 00–Dec 02). The infant groups were divided into thoseV24 weeks’ those25–26 weeks’ and those 27–29 weeks’ gestation. The data was analysed using SPSS for
Windows Version 10.
Results: In the infantsV24 weeks’ there was no change in survival but the rate of severe
ROP (Stagez3) after initially decreasing, has significantly increased to 54%. The
Abstract192
percentage of infants treated has significantly increased to 33%. In the infants 25–26
weeks’ there was a significant increase in survival and the rate of severe ROP has
significantly decreased, but the percentage of infants treated has increased over the four
epochs. In the infants 27–29 weeks’, there was a significant increase in survival and the
rate of severe ROP and those treated has decreased. There was little change in the
percentage of infants examined for ROP over the 11 years.
92–94 95–97 98–00 00–02
23–24 weeks’ survived 41(43.2%) 52 (42.3%) 55 (39.6%) 76 (45.6%)
Stagez3 ROP 17 (41.5%) 16 (30.8%) 23 (41.8%) 41 (53.9%)*
Treated 8 (19.5%) 9 (17.3%) 15 (27.3%) 25 (32.9%)*
Stage 4 ROP 0 2 (3.8%) 1 (1.8%) 3 (3.9%)
25–26 weeks’ survived 211 (63.4%) 269 (69.7%) 249 (71.6%)# 238 (71.9%)# **
Stagez3 55 (26.1%) 56 (20.8%) 41 (16.5%)# 46 (19.3%)***
Treated 19 (9.0%) 21 (7.8%) 24 (9.6%) 32 (13.4%)
Stage 4 2 (0.8%) 1 (0.4%) 2 (0.8%) 3 (1.3%)
27–29 weeks’ survived 729 (87.3%) 737 (90.6%)## 747 (92.2%)# 707 (90.6%)## **
Stagez3 30 (4.2%) 15 (2.0%)## 19 (2.5%) 17 (2.4%)
Treated 14 (1.9%) 7 (0.9%) 8 (1.1%) 8 (1.1%)
Stage 4 5 (0.7%) 0 2 (0.3%) 0
* Significantly increased trend over time pb0.05.
** Significantly increased trend over time pb0.02.
*** Significantly decreased trend over time pb0.05.# Significantly different to 92–94 Epoch pb0.02.## Significantly different to 92–94 Epoch pb0.05.
Conclusion: In NSW and the ACT, the incidence of severe ROP and those treated has
significantly increased in infants V24 weeks’ gestation. This was not the case in the infants
with longer gestational ages. A greater awareness and willingness to treat may be the
reason for these changes.
References
(1) Todd DA et al. ROP in infants b29 weeks’ gestation in NSW from 1986–92, J Paediatr. Child
Health. 1998; 34: 32–36.
(2) Public Health Division. New South Wales Mothers and Babies 2000: NSW Health Bulletin
Supplement. 2001; 12: No. S-3 p. 66.
