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Biomedical subjects

R W Cooke

Publications and source records attributed to R W Cooke.

At least 37 records · Page 2Linked to original sources
PubMed1997

Pentane measurement in ventilated infants using a commercially available system.

The measurement of breath pentane as a marker of lipid peroxidation has recently been criticized. Problems encountered include the coelution of isoprene with pentane, contamination with exogenous pentane, and the influence of elevated oxygen concentration. The aim of this project was to investigate and evaluate the Chrompack 9001 Gas Chromatograph, using thermal desorption and cryofocussing and an Al2O3/KCl PLOT column with FID, for use in the measurement of breath pentane in ventilated preterm infants. We have clearly separated isoprene from n-pentane and used hydrocarbon free air to clear the airways and avoid contamination with exogenous pentane. Samples should be stored in Tedlar bags for a maximum of 48 h and on capped desorption tubes for no longer than 24 h. Patient variability was relatively high (mean 18%, n = 4); thus, all patients were sampled in duplicate. No correlation was found between fractional inspired oxygen concentration (FiO2) and exhaled pentane in preterm infants ventilated for respiratory distress syndrome. In conclusion, we feel that despite the pitfalls and technical difficulties, with careful attention to detail it is possible to reliably measure breath pentane in ventilated preterm infants as an index of lipid peroxidation.

Biomarkers↗
PubMed1997

Attention deficit hyperactivity disorders and other psychiatric outcomes in very low birthweight children at 12 years.

One hundred and thirty-seven very low birthweight (VLBW) children were compared at 12 years with a sample of matched peers on a number of psychiatric symptoms including Attention Deficit/Hyperactivity Disorder, depression, anxiety, and antisocial behaviour using the Child and Adolescent Psychiatric Assessment parent interview and various parent and child questionnaires. The main psychiatric risk was Attention Deficit Hyperactivity (ADH) disorders, with 31/136 (23%) VLBW children meeting clinical criteria, compared to 9/148 (6%) of peers. VLBW children were also more likely to have generalised anxiety and more symptoms of depression. More than one quarter of VLBW children (38/136; 28%) showed a psychiatric disorder of some type compared to 9% (14/148) of peers. VLBW children are at increased risk of psychiatric symptoms especially ADHD. This outcome is discussed in relation to neurological, demographic, and cumulative impairment factors.

Anxiety Disorders↗
PubMed1997

A hypothesis for the aetiology of spastic cerebral palsy--the vanishing twin.

The aetiology of spastic cerebral palsy (CP), in the majority of cases, is not known but the general consensus is that cerebral impairment occurs prepartum. In monochorionic twin pregnancies, death of one twin late in gestation is recognised as being an important risk factor for the surviving cotwin to have CP. It has been suggested that a significant proportion of singletons with spastic CP may be the result of death of a cotwin in the second half of gestation. In this paper it is hypothesised that spastic CP of unknown aetiology is the result of the death of a monochorionic cotwin and that the death of the cotwin may impair the neurological development of the survivor throughout gestation. If so, vanishing-twin syndrome, which is now a recognised phenomenon revealed by ultrasound examination in early pregnancy, is important in the aetiology of spastic CP.

Adult↗
PubMed1997

Differential effects of preterm birth and small gestational age on cognitive and motor development.

AIMS: To determine the differential effects of preterm birth and being small for gestational age on the cognitive and motor ability of the child. METHODS: A longitudinal cohort of all infants of gestational age < or = 32 weeks born to mothers resident in the counties of Cheshire and Merseyside in 1980-1 was studied. The children were assessed at the age of 8 to 9 years using the Wechsler Intelligence Scale for Children, the Neale analysis of reading ability, and the Stott-Moyes-Henderson test of motor impairment. Adequacy of fetal growth was determined by the birthweight ratio--that is, the ratio of the observed birthweight to the expected birthweight for a given gestational age. Children with clinically diagnosed motor, learning or sensory disabilities were excluded. Information on social variables was obtained by a questionnaire completed by the parents. Of the 182 children, 158 were assessed. RESULTS: IQ was positively correlated with birthweight ratio but not with birthweight or gestational age. Motor ability was associated with birthweight, gestational age, and birthweight ratio. Reading comprehension was associated with birthweight ratio, but reading rate and accuracy were best explained by social variables and sex. IQ remained associated with birthweight ratio, after adjusting for maternal education, housing status, and number of social service benefits received. Reading ability was related to these social variables but motor ability was not. CONCLUSIONS: The effects of SGA and preterm birth differed: SGA was associated with cognitive ability, as measured by IQ and reading comprehension; motor ability was additionally associated with preterm birth. Reading rate and accuracy were not associated with SGA or preterm birth but were socially determined.

Birth Weight↗
PubMed1997

Visual impairment in very low birthweight children.

AIMS: To compare the visual function of a cohort of very low birthweight (VLBW) children in early adolescence with that of their normal birthweight peers; to correlate visual impairment in this group with available perinatal data; and to examine the relation between the visual ability of VLBW children and their cognitive and motor skills. METHODS: As part of a long term neurodevelopmental study, 137 VLBW children and 163 normal birthweight controls were visually assessed between the ages of 11 and 13 years. Their eyes were examined for strabismus and movement disorders, and the use of visual correction for refractive errors was noted. Measures were made of visual acuity, stereopsis, and contrast sensitivity. All children had standardised tests of motor ability and cognitive skills. Perinatal data, including cranial ultrasonography results, had been obtained from the children's notes. No data were available however, regarding retinopathy of prematurity as screening was not established when these infants were born. RESULTS: On all measures, the visual function of the VLBW children was poorer than that of the controls. Reduced visual function was present in 63.5% of VLBW children compared with 36% of controls. Poor contrast sensitivity and strabismus were predictive of poor motor skills in the VLBW children. Poor contrast sensitivity and poor visual acuity (at 0.3 metres) were predictive of lower IQ. Low birthweight, intraventricular haemorrhage, intrauterine growth retardation and low 1 minute Apgar scores predicted reduced visual function. CONCLUSIONS: VLBW children have a high incidence of impaired vision. Stereopsis and contrast sensitivity are useful additions to the screening of this high risk group. They identified impaired vision that was not detected by normal screening and were related to impaired neurodevelopmental outcome.

Adolescent↗
PubMed1996

Improved outcome for infants at the limits of viability.

UNLABELLED: Factors associated with survival and freedom from cerebral parenchymal lesions and severe retinopathy were examined in a cohort of 250 extremely preterm infants of less than 26 weeks gestation admitted to a regional neonatal intensive care unit between 1982 and 1993. There were 99 survivors of whom 73 were free of major early morbidity. CONCLUSION: Logistic regression showed that both survival and survival free from early morbidity were independently related to gestation, birth weight, birth period and antenatal steroid prophylaxis.

Birth Weight↗
PubMed1996

Handedness in very-low-birthweight (VLBW) children at 12 years of age: relation to perinatal and outcome variables.

The authors assessed 137 VLBW children and 162 controls for laterality by observation and questionnaire at 12 years of age. A significantly higher proportion of the VLBW children were either left-handed or mixed-handed. A number of motor cognitive and educational outcome variables were measured. Impaired manual dexterity was found to be significantly more common in VLBW non-right-handers. This group was also found to be more at risk of poor near vision. No cognitive or educational outcomes were associated with handedness. The results seem to support the theory that at least in a proportion of VLBW children, non-right-handedness has a pathological basis, but the relationship to perinatal events remains obscure.

Adolescent↗
PubMed1996

Cost of care for a geographically determined population of low birthweight infants to age 8-9 years. I. Children without disability.

AIM: To determine the extra cost of healthcare associated with low birthweight, in a cohort study of a geographically defined population in five health districts that comprise Merseyside. METHODS: The study comprised all children of birthweight < or = 1500 g and a 10% random sample of those weighing 1501-2000 g, without clinical disability, born in 1980 and 1981 to mothers resident in Merseyside, and their controls, matched by age, sex, and school class, followed up to age 8-9 years. RESULTS: The cost of care associated with the initial admission to the neonatal special/intensive care unit and subsequent use of hospital and family practitioner services was assessed. There were 641 survivors without disability and 227 non-survivors who weighed < or = 2000 g at birth. The mean cost of neonatal care per low birthweight child was 13 times greater than for a control child. For children weighing < or = 1000 g at birth, neonatal costs were 55 times greater than for the control children. Low birthweight children continue to use hospital and family practitioner services more intensively than controls to age 8-9 years. CONCLUSION: Low birthweight children used hospital and family practitioner services more intensively throughout the follow up period. Whether the increased use of health services persists into adolescence and adulthood is yet to be determined.

Child Care↗
PubMed1996

Cost of care for a geographically determined population of low birthweight infants to age 8-9 years. II. Children with disability.

AIM: To determine the cost of health and educational service provision for low birthweight children with a clinical disability. METHODS: Cohort study of a geographically defined population in five health districts that comprise the County of Merseyside was undertaken. All children with a clinical disability born in 1980 and 1981 to mothers resident in the County of Merseyside were followed up to age 8-9 years. The cost of care associated with the initial admission to the neonatal special/intensive care unit and subsequent use of hospital, family practitioner, and special education services was assessed. RESULTS: There were 52 children with a disability; the disability rate in children of birthweight < or = 2000 g was estimated at 7.7%. Of the total expenditure to age 8-9 years, special education was the largest category (52%) and neonatal care accounted for 35%. The disabled children accounted for 38% of the cost of the whole cohort of 693 disabled and non-disabled children who weighed < or = 2000 g at birth. CONCLUSION: In a cohort of low birthweight children, those who are disabled account for a disproportionate amount of the total expenditure to age 8-9. The cost of long term care for disabled young persons and adults will increasingly dominate the cost of care for the whole cohort of low birthweight children.

Child Care↗
PubMed1996

Growth impairment in very low birthweight children at 12 years: correlation with perinatal and outcome variables.

AIM: To compare the growth of very low birthweight (VLBW) children in early adolescence with that of their normal birthweight peers; to examine the role of factors contributing to growth-parental height, perinatal variables, bone maturity and sexual maturation; to examine the correlation between head growth and cognitive and educational outcome. METHODS: Standing and sitting heights, weight, occipito-frontal circumference (OFC), skinfold thicknesses and pubertal staging were assessed in 137 VLBW children and 160 controls at 11-13.5 years of age. Ninety six (70%) of the VLBW children had their bone age assessed using the TW2 method. Reported parental heights were obtained by questionnaire. All children had standardised tests of cognitive and educational ability. Perinatal data had been collected prospectively as part of a longitudinal study. RESULTS: VLBW children had lower heights, weight, and OFC. Skinfold thicknesses were no different. The children's short stature was not accounted for by difference in parental height, degree of pubertal development, or by retarded bone age. Indeed, the TW2 RUS score was significantly advanced in the VLBW children. Using the bone ages to predict final adult height, 17% have a predicted height below the third centile and 33% below the tenth. Weight was appropriate for height, but there was a residual deficiency in OFC measurements after taking height into account. In the VLBW group smaller head size was associated with lower IQ and mathematics and reading scores. CONCLUSIONS: Growth problems persist in VLBW children and final heights may be even more abnormal than present heights suggest. VLBW children have smaller OFCs than expected from their short stature alone and this may be associated with poorer educational and cognitive outcomes.

Adolescent↗
PubMed1995

Randomised controlled trial of allopurinol prophylaxis in very preterm infants.

Allopurinol, an inhibitor of xanthine oxidase (an enzyme capable of generating superoxide radicals following hypoxiaischaemia), was investigated in preterm infants to determine its ability to prevent the complications of neonatal intensive care which may be associated with oxidative injury. Four hundred infants of between 24 and 32 weeks' gestation were randomly allocated to receive enteral allopurinol (20 mg/ml) or an equivalent dose of placebo for seven daily doses. At admission, plasma hypoxanthine concentrations were significantly higher in infants who subsequently developed periventricular leucomalacia (PVL), bronchopulmonary dysplasia (BPD), or retinopathy of prematurity (ROP), but there was no difference in the primary endpoint (PVL) between the treated and control groups. The failure of allopurinol prophylaxis in this group of infants is probably related to the complex nature of the pathological processes and to the timing of treatment. If oxidant injury is an important mechanism of cellular injury in these preterm infants, an alternative biochemical modulator would be required, or a combination of agents might be effective.

Allopurinol↗
PubMed1995

Motor impairment in children 12 to 13 years old with a birthweight of less than 1250 g.

AIM: To determine whether poor motor skills, previously identified in a cohort of very low birthweight (< 1250 g) children, born in 1980-1, have persisted or improved. Previous assessments had shown significant improvement between the ages of 6 and 8 years. METHODS: The original cohort were traced and were assessed using the Movement Assessment Battery for Children, an update of the Test Of Motor Impairment, used at 6 and 8 years. Where possible the classroom-matched controls from the original studies were assessed, otherwise new controls were selected. Teachers were also asked to identify those children whom they considered clumsy. Forty seven of the original cohort of 53 children, all but one still attending mainstream school, and 40 original and 20 new classroom-matched controls were studied. RESULTS: Fifty one per cent of the cohort showed clinically important or borderline impairment. More of these children had significant impairment (16/47, 34%) than the controls (3/60, 5%). The improvement seen by 8 years of age was maintained but there was no further improvement. Girls had significantly higher overall impairment scores (median 16; interquartile range 10-21.5) than the boys (5.5 (1.5-12.5)), and on a wider variety of subtests (5/8) than the boys (3/8). CONCLUSIONS: Many very low birthweight children have impaired motor skills. Despite early improvement it persists into adolescence and the deficit remains. Interventional studies may help to see if these problems can be alleviated.

Adolescent↗
PubMed1994

Somatosensory evoked potentials following posterior tibial nerve stimulation predict later motor outcome.

Posterior tibial nerve somatosensory evoked potentials (PTN-SEPs) were performed on 50 neonates at high risk of future neurodevelopmental impairment just before their discharge from the neonatal intensive-care unit. The close association of sensory pathways with motor tracts and the need for sensory input and integration for normal motor functioning would indicate that CNS lesions producing motor deficits may be detected by this method. Follow-up of these infants revealed a highly significant relationship between bilaterally abnormal PTN-SEPs and the presence of cerebral palsy at three years of age. Normal PTN-SEPs were associated with a normal outcome in 24 of 25 infants. In this group of neonates, PTN-SEPs were more predictive than cranial ultrasound.

Brain Diseases↗
PubMed1994

Clinical and subclinical deficits at 8 years in a geographically defined cohort of low birthweight infants.

OBJECTIVE: To determine the prevalence of subclinical deficits in cognitive and motor function in low birthweight infants. DESIGN: Children of birth weight < or = 2000 g born to mothers resident in Merseyside in 1980-1 assessed using the Wechsler Intelligence Scale for Children (WISC), the Neale analysis of reading ability, and the Stott-Moyes-Henderson test of motor impairment (TOMI). Children attending normal schools assessed with controls matched for age, sex, and class in school. Children attending special schools were assessed unmatched. SUBJECTS: 233 matched index case-control pairs attending normal primary schools and 46 unmatched children attending special schools. SETTING: Primary and special schools. MAIN OUTCOME MEASURES: IQ score, reading age in months, and TOMI score. RESULTS: Index cases when compared with controls had a lower WISC score (mean IQ difference 8.8; 95% confidence interval (CI) 6.8 to 10.7), a lower reading age (mean difference 6.5 months; 95% CI 4.0 to 9.0), and poorer motor performance as shown by the TOMI score (mean difference 1.4; 95% CI 1.1 to 1.8). Of the children attending special schools, 23/46 (50%) had a WISC score < or = 50. CONCLUSIONS: Low birthweight children have significant subclinical deficits of cognitive and motor function and extra resources, especially in education, may be required to meet their needs.

Birth Weight↗
PubMed1994

Prevalence of behaviour disorders in low birthweight infants.

OBJECTIVE: To determine the prevalence of behaviour disorders in low birthweight infants. DESIGN: Children of birth weight < or = 2000 g born to mothers resident in Merseyside in 1980-1 assessed using the Rutter parent and teacher behaviour questionnaires and the Conner modification of the Rutter teacher questionnaire. Children attending normal schools were assessed with controls matched for age, sex, and class in school. Children attending special schools were assessed unmatched. SUBJECTS: 233 matched case-control pairs attending normal primary schools and 46 unmatched children attending special schools. SETTING: Primary and special schools. MAIN OUTCOME MEASURES: Emotional, conduct, and undifferentiated behaviour disorders and hyperactivity. RESULTS: On the parental questionnaire screen, 36% of the cases and 22% of the controls had a behaviour disorder and on the teacher questionnaire the proportions were 27% and 12% respectively. Hyperactivity was significantly more common among male cases than their controls (21% v 5.0%) but differed little among female cases and controls (9% v 7%). CONCLUSIONS: Improving neonatal survival of low birthweight infants is accompanied by a higher prevalence of behaviour disorders. The long term implications for psychiatric morbidity and other adult disease must be monitored.

Behavior↗
PubMed1994

Factors affecting survival and outcome at 3 years in extremely preterm infants.

A total of 823 infants born at 28 weeks' gestation or less were admitted to a regional referral unit between 1980 and 1989. Four hundred and sixty five (56.5%) survived to be discharged home. Twenty one subsequently died and two were lost to follow up. Four hundred and forty two (53.7%) were assessed for disabilities at the age of 3 years. Eighty four (19%) had major disabilities, of which 40 (9%) were severe. A further 39 (9%) had lesser disabilities. Three hundred and nineteen (63%) survivors appeared to be functioning normally. Logistic regression showed the likelihood of survival to be independently related to gestational age, birthweight ratio, and more recent year of birth, and inversely related to male sex and ultrasound evidence of cerebral haemorrhage or infarction. The likelihood of later disability in survivors was only independently related to cerebral ultrasound appearances.

Birth Weight↗