Search PubMed⌕ Search

Biomedical subjects

N Butler

Publications and source records attributed to N Butler.

At least 19 recordsLinked to original sources
PubMed2005

Discovery of the short gamma-ray burst GRB 050709.

Gamma-ray bursts (GRBs) fall into two classes: short-hard and long-soft bursts. The latter are now known to have X-ray and optical afterglows, to occur at cosmological distances in star-forming galaxies, and to be associated with the explosion of massive stars. In contrast, the distance scale, the energy scale and the progenitors of the short bursts have remained a mystery. Here we report the discovery of a short-hard burst whose accurate localization has led to follow-up observations that have identified the X-ray afterglow and (for the first time) the optical afterglow of a short-hard burst; this in turn led to the identification of the host galaxy of the burst as a late-type galaxy at z = 0.16 (ref. 10). These results show that at least some short-hard bursts occur at cosmological distances in the outskirts of galaxies, and are likely to be caused by the merging of compact binaries.

Journal Article↗
PubMed2005

Association of the dopamine transporter (DAT1) 10/10-repeat genotype with ADHD symptoms and response inhibition in a general population sample.

Association between attention-deficit hyperactivity disorder (ADHD) and the 10-repeat allele of the dopamine transporter gene (DAT1) has been reported in independent clinical samples using a categorical clinical definition of ADHD. The present study adopts a quantitative trait loci (QTL) approach to examine the association between DAT1 and a continuous measure of ADHD behaviours in a general-population sample, as well as to explore whether there is an independent association between DAT1 and performance on neuropsychological tests of attention, response inhibition, and working memory. From an epidemiological sample of 872 boys aged 6-11 years, we recruited 58 boys scoring above the 90th percentile for teacher reported ADHD symptoms (SWAN ADHD scale) and 68 boys scoring below 10th percentile for genotyping and neuropsychological testing. A significant association was found between the DAT1 homozygous 10/10-repeat genotype and high-scoring boys (chi(2)square=4.6, P<0.03; odds ratio=2.4, 95% CI 1.1-5.0). Using hierarchical linear regression, a significant independent association was found between the DAT1 10/10-repeat genotype and measures of selective attention and response inhibition after adjusting for age, IQ, and ADHD symptoms. There was no association between DAT1 and any component of working memory. Furthermore, performance on tasks of selective attention although associated with DAT1 was not associated with SWAN ADHD high scores after controlling for age and IQ. In contrast, impairment on tasks that tapped sustained attention and the central executive component of working memory were found in high-scoring boys after adjusting for age and IQ. The results suggest that DAT1 is a QTL for continuously distributed ADHD behaviours in the general population and the cognitive endophenotype of response inhibition.

Attention↗
PubMed2002

Bother arising from urinary frequency in women.

Patients commonly express bother with the symptom of frequent urination. The relationship between actual voiding frequency and this symptom is undocumented. We reviewed records of 200 women who had completed 24-hour frequency-volume charts, and had indicated their degree of bother with urinary frequency utilizing the short form of the Urogenital Distress Inventory. The degree of bother was correlated with daytime and nighttime voiding frequency, maximum functional capacity, mean voided volume, and demographic variables. Among 200 women, 180 (90%) indicated at least a minor degree of bother with urinary frequency. A voiding frequency of eight or more times in 24 hours was reported by 166 (83%) of women. Among the 34 women voiding fewer than eight times/24 hours, 26 (76%) reported bother with urinary frequency. There was large variation in the degree of bother reported at a given voiding frequency. Postmenopausal women without hormone replacement therapy (HRT) recorded more nighttime voids than those on HRT. Among postmenopausal women without HRT, mean voided volume and maximum functional capacity were inversely related to patient age. Our study suggests that the currently utilized cutoff value of eight daily voids to define urinary frequency, may not be helpful in the management of women in this country. A racially diverse study of the voiding habits of asymptomatic North American women is mandated.

Adult↗
PubMed2001

Laparoscopic antireflux surgery in the elderly.

BACKGROUND: Laparoscopic antireflux surgery is frequently denied to older patients with gastroesophageal reflux disease (GERD) because of a perceived higher operative complication rate, a decreased impact of the intervention on quality of life, and decreased cost effectiveness. This study compares disease severity, surgical outcomes, and impact on quality of life between elderly and young patients with GERD. METHODS: Patients were selected from a prospectively maintained database of 1100 patients who underwent various laparoscopic esophageal procedures at our institution. Only patients having chronic intractable GERD and a minimum 6 months' follow-up were included in the study. Thirty elderly patients with a mean age of 71.2 years (SD +/- 5.6) were compared with a group of 30 younger patients (mean age, 43.9 +/- 12.8 years). Comparisons were made between subjective and objective outcomes, operative results, and health-related quality of life (HQRL) scores using SF-36 instruments. RESULTS: The preoperative symptom assessment scores presenting frequency of symptoms on a 0-4 scale), and preoperative pH and manometry data were comparable in the two groups. Elderly patients had significantly higher ASA (American Society of Anesthesiologists) scores. Each group demonstrated a significant improvement in the postoperative symptom assessment scores and the esophageal functional studies (p<0.05). However, no significant differences were found in terms of postoperative complications, postoperative hospital stay, postoperative symptom scores, Demeester scores, or the HRQL data. CONCLUSION: Laparoscopic antireflux surgery in elderly patients improves acid reflux and appears to be safe and effective as measured by postoperative testing in elderly and young patients.

Adult↗
PubMed2001

Pregnancy smoking and childhood conduct problems: a causal association?

Recent investigations have highlighted associations between maternal smoking in pregnancy and antisocial behaviour in offspring, and suggested the possibility of a causal effect. We used data from the 1970 British birth cohort study (BCS70) to examine these links in a large. population-based sample studied prospectively from birth to age 16. We found a strong dose-response relationship between the extent of pregnancy smoking and childhood-onset conduct problems, but no links with adolescent-onset antisocial behaviours. Effects on childhood-onset conduct problems were as marked for girls as for boys, and were robust to controls for a variety of social background factors and maternal characteristics. Controls for mothers' subsequent smoking history modified this picture, however, suggesting that the prime risks for early-onset conduct problems may be associated with persistent maternal smoking--or correlates of persistent smoking--rather than with pregnancy smoking per se.

Adolescent↗
PubMed2000

4.0 Tesla magnetic resonance imaging of brainstem lesions with ocular motility deficits.

The authors studied six patients with brainstem ocular motility deficits with 4.0 Tesla (T) magnetic resonance imaging to investigate whether a higher field strength would produce superior images compared with 1.5T. In four patients whose lesions were evident on 1.5T, the increased signal-to-noise achieved with 4.0T allowed for better resolution at 1-mm slice thickness than was achieved at the standard 5-mm slice thickness with 1.5T. In the two patients with unremarkable 1.5T scan results, 4.0T also failed to demonstrate a lesion. Therefore, 4.0T imaging has superior resolution to 1.5T imaging and can provide more detailed images of lesions identified by 1.5T.

Adolescent↗
PubMed1998

[Mutational screening of peripherin/RDS genes, rhodopsin and ROM-1 in 69 index cases with retinitis pigmentosa and other retinal dystrophies].

PURPOSE: Phenotypic, genetic and molecular characterization of 69 index patients with retinitis pigmentosa (RP) and various inherited retinal diseases. PATIENTS AND METHOD: patients went through complete ocular examination and blood samples were drawn for mutational screening of three candidate genes: rhodopsin (RHO), peripherin/RDS, and ROM-1. RESULTS: the most frequent type of RP among our population was the autosomal dominant (43.6%). Three RHO mutations were found among the RP patients. A RDS mutation was detected in three unrelated families segregating dominant macular dystrophy. DISCUSSION AND CONCLUSIONS: 18% of the autosomal dominant RP patients presented a RHO mutation; RDS R172W mutation was present in 25% of the dominant macular dystrophies.

Adult↗
PubMed1997

Investigation into the increase in hay fever and eczema at age 16 observed between the 1958 and 1970 British birth cohorts.

OBJECTIVE: To investigate whether changes in certain perinatal and social factors explain the increased prevalence of hay fever and eczema among British adolescents between 1974 and 1986. DESIGN: Two prospective birth cohort studies. SETTING: England, Wales, and Scotland. SUBJECTS: 11,195 children born 3-9 March 1958 and 9387 born 5-11 April 1970. MAIN OUTCOME MEASURES: Parental reports of eczematous rashes and of hay fever or allergic rhinitis in the previous 12 months at age 16. RESULTS: The prevalence of the conditions over the 12 month period increased between 1974 and 1986 from 3.1% to 6.4% (prevalence ratio 2.04 (95% confidence interval 1.79 to 2.32)) for eczema and from 12.0% to 23.3% (prevalence ratio 1.93 (1.82 to 2.06)) for hay fever. Both conditions were more commonly reported among children of higher birth order and those who were breast fed for longer than 1 month. Eczema was more commonly reported among girls and hay fever among boys. The prevalence of hay fever decreased sharply between social classes I and V, increased with maternal age up to the early 30s, and was lower in children whose mothers smoked during pregnancy. Neither condition varied significantly with birth weight. When adjusted for these factors, the relative odds of hay fever (1986 v 1974) increased from 2.23 (2.05 to 2.43) to 2.40 (2.19 to 2.63). Similarly, the relative odds of eczema rose from 2.02 (1.73 to 2.36) to 2.14 (1.81 to 2.52). CONCLUSIONS: Taken together, changes between cohorts in sex, birth weight, birth order, maternal age, breast feeding, maternal smoking during pregnancy, and father's social class at birth did not seem to explain any of the observed rise in the prevalence of hay fever and eczema. However, correlates of these factors which have changed over time may still underlie recent increases in allergic disease.

Adolescent↗
PubMed1996

Sports participation and emotional wellbeing in adolescents.

BACKGROUND: Regular physical activity may have psychological benefits. Our study assessed the association between extent of participation in regular sport or vigorous recreational activity and emotional wellbeing in adolescents aged 16 years. METHODS: Data were collected from a cohort of adolescents, born between April 5 and April 11, 1970, in England, Scotland, and Wales, who took part in the follow-up assessment at age 16 years. Emotional wellbeing was assessed by the general health questionnaire (GHQ) and the malaise inventory (divided into psychological and somatic subscales). Information was obtained about participation in ten team and 25 individual sports and vigorous recreational activities during the previous year. Non-vigorous recreations, such as darts and snooker, were assessed separately. Social class and health status (recent illness and use of hospital services) were included in our analyses as possible confounding factors. 2223 boys and 2838 girls with a mean age of 16.3 years (SD 0.38) were included in our analysis. Statistical analysis was by multiple linear and logistic regression. FINDINGS: The sport and vigorous recreational activity index was positively associated with emotional wellbeing independently of sex, social class, health status, and use of hospital services. These associations were significant for the psychological symptom subscale of the malaise inventory (regression coefficient -0.024, 95 percent Cl -0.036 to -0.011, p<0.001) and the GHQ (odds ratio of emotional distress per unit increase in vigorous physical activity 0.992, 95 percent Cl 0.985-0.998, p<O.O1). By contrast, participation in non-vigorous activities was associated with high psychological and somatic symptoms on the malaise inventory. INTERPRETATION: We conclude that emotional wellbeing is positively associated with extent of participation in sport and vigorous recreational activity among adolescents. Although causal associations cannot be assumed in this cross-sectional analysis, our results are consistent with experimental evidence that vigorous exercise has favourable effects on emotional state.

Adolescent↗
PubMed1996

Study of the aetiology of wheezing illness at age 16 in two national British birth cohorts.

BACKGROUND: Data from two national British birth cohorts were used to measure the increase in prevalence of wheezing illness at age 16 between 1974 and 1986, and to investigate the role of several potential risk factors in the increase. METHODS: The occurrence of self-reported asthma or wheezy bronchitis within the past year, and the frequency of attacks of wheezing illness at age 16, were compared in 11,262 and 9266 children born in one week of 1958 and 1970, respectively. The effects of several putative risk factors for asthma--including birth weight, maternal age, birth order, breast feeding, maternal smoking in pregnancy, child's personal smoking, and father's social class--on the change in occurrence of wheezing illness at age 16 were assessed by multiple logistic regression. RESULTS: The annual period prevalence of asthma or wheezy bronchitis at age 16 increased from 3.8% in 1974 to 6.5% in 1986 (prevalence ratio (PR) = 1.71, 95% CI 1.52 to 1.93). The proportion of children experiencing attacks more than once a week increased from 0.2% to 0.7% (PR = 3.77, 95% CI 2.28 to 6.23). The prevalence of self-reported eczema and hayfever within the past year doubled between 1974 and 1986, suggesting that the increase in asthma was part of a general increase in the prevalence of atopic disease. However, in the complete dataset, after adjustment for the effects of the risk factors studied, the prevalence odds ratio for asthma or wheezy bronchitis in 1986 compared with 1974 was virtually unchanged from the unadjusted value at 1.77 (95% CI 1.46 to 2.15). CONCLUSION: The prevalence of wheezing illness in British teenagers increased by approximately 70% between 1974 and 1986. This increase appears to have occurred in the context of a general increase in atopic disease and was largely unexplained by changes in the distribution of maternal age, birth order, birth weight, infant feeding, maternal smoking, active smoking by the child, or father's social class.

Adolescent↗
PubMed1996

Full characterization of the maculopathy associated with an Arg-172-Trp mutation in the RDS/peripherin gene.

The objective of this study was to fully characterize the macular dystrophy phenotype and genotype in a large family of the Zermatt area of Switzerland. Clinical and molecular studies of the family included a comprehensive eye examination and a mutational analysis of the RDS, rhodopsin, and TIMP-3 genes. In selected cases, fluorescein angiography, perimetry, and electroretinography were performed. Forty-two family members at risk of expressing the maculopathy were studied. Of these, 24 were found to be clinically affected. The severity of macular disease in these patients was clearly age-related and different stages of progression were identified. Central pigmentary alterations were seen in adolescent patients, while patients in their late teens and twenties exhibited drusen-like deposits. Later, these defects formed focal areas of atrophy which eventually led to central geographic atrophy with severe visual loss by the fifth decade and cone-rod dysfunction. The transmission of this condition is autosomal dominant with complete penetrance. The underlying genetic defect is a mutation in codon 172 of the RDS/peripherin gene, a gene expressed in both rods and cones, which results in the substitution of tryptophan for an arginine residue at that position. 'Zermatt macular dystrophy' is a dominant, age-related, progressive macular dystrophy which in later stages resembles atrophic age-related macular degeneration. The size of the family studied allowed definition of the clinical spectrum of this condition and identification of the related genetic defect which allows more precise diagnosis and counseling.

Adult↗
PubMed1996

Rehabilitation of ten soldiers with exertional rhabdomyolysis.

This case study describes the rehabilitation of 10 active duty U.S. soldiers with exertional rhabdomyolysis. The pathophysiology of rhabdomyolysis is discussed. The initial management is concerned with accurate diagnosis and monitoring of laboratory values to prevent complications. Active and passive range of motion, strength, and induration were used as indicators of recovery. The goal of rehabilitation was to safely return patients to their basic training units without activity restrictions as quickly as possible. All 10 soldiers were able to pass the Army Physical Fitness Test at the end of their training cycle. For those patients with rhabdomyolysis who desire to return to a high level of function, close monitoring of exercise intensity appears to allow for a safe, expedient return to previous levels of function. This description of a rare disorder will increase awareness and stimulate discussion so that more specific guidelines for rehabilitation can be developed.

Adolescent↗
PubMed1995

Reversible hepatic dysfunction in association with cyclophosphamide therapy.

A 5.5-year-old child with nephrotic syndrome was treated with cyclophosphamide. After 9 weeks of therapy she developed jaundice and abnormal liver function tests. No infective aetiology was found and the abnormal liver function tests resolved within 5 weeks of discontinuing cyclophosphamide. Cyclophosphamide has rarely been reported to cause liver dysfunction, but not in children treated for nephrotic syndrome, and paediatricians should therefore be aware of its potential for inducing reversible hepatic dysfunction.

Child, Preschool↗
PubMed1995

Prospective study of risk factors for early and persistent wheezing in childhood.

The object of this study was to determine the relative importance of low birth weight, preterm birth, low maternal age, household size, exposure to maternal smoking, personal smoking at 16 yrs of age, early termination of breastfeeding and socioeconomic status in the aetiology of wheezing illness in the first 5 yrs of life, and on the persistence of this illness at 16 yrs of age. In 15,712 children born in Britain during one week of April 1970, the occurrence of wheezing by 5 yrs of age, and of wheezing in the past year at 16 yrs of age within this group were analysed in multivariate logistic regression against each potential risk factor. The independent determinants of wheezing by 5 yrs of age were male sex, maternal smoking during pregnancy (odds ratio (OR) for 15+ cigarettes.day-1 = 1.39; 95% confidence interval (95% CI) 1.22-1.58) and low birthweight (OR for birthweight < 2.5 kg = 1.26; 95% Cl 1.07-1.50). Of children who had wheezed by 5 yrs of age, 15% reported wheezing in the past 12 months at 16 yrs of age. The persistence of symptoms at 16 yrs of age was independently related to low maternal age (OR for 20 vs 40 yrs of age = 1.96; 95% CI 1.08-3.45) and to high social status (OR for most vs least advantaged = 1.95; 95% CI 1.13-3.38). We conclude that low birth weight and maternal smoking in pregnancy are independent risk factors for early childhood wheezing, but in 85% of children with early wheezing it resolves by 16 yrs of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

A high incidence of asthma and respiratory symptoms in 4-11 year old children.

A study assessing the prevalence of respiratory symptoms in two primary schools in Birmingham, U.K. was performed. A questionnaire was delivered to pupils in both schools after which three open days were conducted in one of the schools, where probable asthmatics were identified and referred to their General Practitioner, Chest Clinic or a school asthma clinic. In this school 49% of responders and 52.9% in the control school were symptomless on questionnaire: 31% and 20.8%, respectively, had probable asthma, falling to 20% and 15.5% if a positive response to the question on recent recurrent wheeze was disregarded as indicating asthma. Using the total population as a denominator, the overall asthma prevalence was 20% which is significantly higher compared to previous English rates. Forty-two were seen at the Chest Clinic, 14 being followed for more than two visits. None were on regular anti-asthma treatment initially; 12/14 were taking prophylactic treatment on follow-up. In the two schools, 10.0% and 14.2% of responders were 'chesty' with 'colds' having no other typical asthmatic symptoms: these children should be studied further. This high incidence of respiratory symptoms in primary school children could represent a national trend or just a local increase.

Ambulatory Care Facilities↗
PubMed1986

Child behavior and accidental injury in 11,966 preschool children.

Social and behavioral characteristics of 11,966 British children, aged 5 years, and mothers' reports of accidental injuries between birth and age 5 years were analyzed. Aggressive behavior was associated with all accidental injuries after controlling psychosocial variables including social class; crowding; mother's psychological distress, age, and marital status; and child's sex. Overactivity was associated only with injuries not resulting in hospitalization after control of the covariates. The relative risk of injuries resulting in hospitalization was 1.9 among children with both high activity and high aggression scores compared with children with low scores on both behavioral scales. The findings support the inference that aggression and overactivity are independently associated with accidents. The associations between child behavior and injuries were stronger than the associations between injuries and the social factors including social class and crowding. This finding suggests that interventions aimed at high-risk groups may be effective supplements to environmental interventions.

Accident Proneness↗