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E Taylor

Publications and source records attributed to E Taylor.

At least 37 records · Page 2Linked to original sources
PubMed2001

Attention deficit hyperactivity disorder (ADHD) and the dopamine D4 receptor gene: evidence of association but no linkage in a UK sample.

Recent studies report association and linkage between attention deficit hyperactivity disorder (ADHD) and the 7-repeat allele of a 48 base-pair repeat in the dopamine D4 receptor gene (DRD4). We examined the frequency of this allele in a sample of probands with DSM-IV ADHD using a case-control design, as well as the transmission disequilibrium test (TDT) and haplotype-based haplotype relative risk (HHRR) in the subset of probands with DNA available from both parents. One hundred and thirty-two ADHD probands were compared with 189 controls (chi(2) = 6.17, 1 df, P = 0.01, OR = 1.73, 95% CI = 1.11--2.71). A total of 85 complete trios were available for within-family tests of association and linkage. Fifty-two heterozygous parents carrying one copy of the 7-repeat were informative for the TDT (29 transmitted vs 23 non-transmitted, chi(2) = 0.69). Analysis of the entire sample of 132 probands using TRANSMIT provided no additional evidence for excess transmission of the 7-repeat allele (58 transmitted vs 54 non-transmitted). HHRR gave similar results. We conclude that the case-control findings are likely to be falsely positive, resulting from genetic stratification. However we can not rule out alternative explanations of low statistical power and gene-environment correlation.

Alleles↗
PubMed2001

Association study of a dopamine transporter polymorphism and attention deficit hyperactivity disorder in UK and Turkish samples.

Molecular genetic studies in attention deficit hyperactivity disorder (ADHD) have focussed on candidate genes within the dopamine system, which is thought to be the main site of action of stimulant drugs, the primary pharmacological treatment of the disorder. Of particular interest are findings with the dopamine transporter gene (DAT1), since stimulant drugs interact directly with the transporter protein. To date, there have been eight published association studies of ADHD with a 480 base-pair allele of a variable number tandem repeat (VNTR) polymorphism in the 3'-untranslated region of the gene, five that support an association and three against. We have analysed the same VNTR marker in a dataset of UK Caucasian children and an independent dataset of Turkish Caucasian children with DSM-IV ADHD, using the transmission disequilibrium test (TDT). Results from the UK (chi(2) = 8.97, P = 0.001, OR = 1.95), but not the Turkish sample (chi(2) = 0.93, P = 0.34) support association and linkage between genetic variation at the DAT1 locus and ADHD. When considered alongside evidence from other published reports, there is only modest evidence for the association, consistent with a very small main effect for the 480-bp allele (chi(2) = 3.45, P = 0.06, OR = 1.15), however we find significant evidence of heterogeneity between the combined dataset (chi(2) = 22.64, df = 8, P = 0.004).

3' Untranslated Regions↗
PubMed2001

Prospective randomized comparison of the safety and effectiveness of placement of endocardial pacemaker and defibrillator leads using the extrathoracic subclavian vein guided by contrast venography versus the cephalic approach.

The purpose of this prospective randomized study was to compare the safety and efficacy of the cephalic approach versus a contrast-guided extrathoracic approach for placement of endocardial leads. Despite an increased incidence of lead fracture, the intrathoracic subclavian approach remains the dominant approach for placement of pacemaker and implantable defibrillator leads. Although this complication can be prevented by lead placement in the cephalic vein or by lead placement in the extrathoracic subclavian or axillary vein, these approaches have not gained acceptance. A total of 200 patients were randomized to undergo placement of pacemaker or implantable defibrillator leads via the contrast-guided extrathoracic subclavian vein approach or the cephalic approach. Lead placement was accomplished in 99 of the 100 patients randomized to the extrathoracic subclavian vein approach as compared to 64 of 100 patients using the cephalic approach. In addition to a higher initial success rate, the extrathoracic subclavian vein medial approach was determined to be preferable as evidenced by a shorter procedure time and less blood loss. There was no difference in the incidence of complications. In conclusion, these results demonstrate that lead placement in the extrathoracic subclavian vein guided by contrast venography is effective and safe. It was also associated with no increased risk of complications as compared with the cephalic approach. These findings suggest that the contrast-guided approach to the extrathoracic portion of the subclavian vein should be considered as an alternative to the cephalic approach.

Aged↗
PubMed2001

An auditable protocol for treating attention deficit/hyperactivity disorder.

We present an auditable protocol for attention deficit/hyperactivity disorder (ADHD) or hyperkinetic disorder. The protocol is derived from standard recommendations and evidence, and is intended for outpatient medical clinic practice in secondary care. Suggested side effect rating scales are included.

Algorithms↗
PubMed2001

Predictors of later schizophrenia and affective psychosis among attendees at a child psychiatry department.

BACKGROUND: Schizophrenia has been linked with psychological problems in childhood but there is little information on precursors of affective psychosis. AIMS: To compare childhood psychological antecedents of adult schizophrenia and affective psychosis. METHOD: Childhood item sheets, which give standardised information on signs and symptoms of mental illness in the year preceding assessment are completed for all attendees at the children's department of the Maudsley and Bethlem Royal Hospital. We examined item sheet data on individuals with an adult diagnosis of schizophrenia (n=59) or affective psychosis (n=27) and a comparison group with no adult mental illness (n=86) (all had attended the department). RESULTS: Abnormal suspiciousness or sensitivity and relationship difficulties with peers are associated with later schizophrenia. In contrast, affective psychosis is associated with childhood hysterical symptoms and disturbances in eating. CONCLUSIONS: Childhood psychological precursors for schizophrenia and affective psychosis differ and do not simply reflect non-specific psychiatric disturbance in adolescence.

Adolescent↗
PubMed2001

Neuropsychological analyses of impulsiveness in childhood hyperactivity.

BACKGROUND: Neuropsychological analyses of impulsiveness are needed to refine assessment of attention-deficit hyperactivity disorder (ADHD). AIMS: To investigate specific impairments in hyperactive children in a neuropsychological task battery of impulsiveness, the Maudsley Attention and Response Suppression (MARS) task battery, and to identify the neural substrates. METHOD: Impulsiveness was assessed using different tasks of inhibitory control and time management (MARS) in 55 children with ADHD, other diagnoses and controls. Functional magnetic resonance images were obtained from adolescents with and without ADHD during three of the tasks. RESULTS: Children with ADHD, but not psychiatric controls, were impaired on tests of response inhibition, but not of motor timing. Reduced right prefrontal activation was observed in hyperactive adolescents during higher level inhibition and delay management, but not during simple sensorimotor coordination. CONCLUSIONS: Attention-deficit hyperactivity disorder is characterised by specific deficits in tasks of motor response inhibition, but not motor timing, and by dysfunction of frontostriatal brain regions.

Adolescent↗
PubMed2001

Sequence verification as quality-control step for production of cDNA microarrays.

To generate cDNA arrays in our core laboratory, we amplified about 2300 PCR products from a human, sequence-verified cDNA clone library. As a quality-control step, we sequenced the PCR products immediately before printing. The sequence information was used to search the GenBank database to confirm the identities. Although these clones were previously sequence verified by the company, we found that only 79% of the clones matched the original database after handling. Our experience strongly indicates the necessity to sequence verify the clones at the final stage before printing on microarray slides and to modify the gene list accordingly.

Gene Library↗
PubMed2001

Comparative evaluation of laser-based microarray scanners.

Laboratories use different laser-based scanners to scan microarray images. To assess whether results from different scanners are comparable, and thus whether data from different laboratories can be compared, we scanned the same microarray slide with three commercial scanners that use different imaging techniques. After the acquisition of the microarray images produced by the three scanners, the images were quantified using a single imaging software package and protocol. The results were compared, and we found that the data obtained from the three scanners were comparable and that the variations caused by the use of different instruments were negligible, in spite of the fact that the scanners were based on different optical imaging techniques.

Carbocyanines↗
PubMed2000

Evaluation of study patients with Lyme disease, 10-20-year follow-up.

To determine the long-term impact of Lyme disease, we evaluated 84 randomly selected, original study patients from the Lyme, Connecticut, region who had erythema migrans, facial palsy, or Lyme arthritis 10-20 years ago and 30 uninfected control subjects. The patients in the 3 study groups and the control group did not differ significantly in current symptoms or neuropsychological test results. However, patients with facial palsy, who frequently had more widespread nervous system involvement, more often had residual facial or peripheral nerve deficits. Moreover, patients with facial palsy who did not receive antibiotics for acute neuroborreliosis more often now had joint pain and sleep difficulty and lower scores on the body pain index and standardized physical component sections of the Short-Form 36 Health Assessment Questionnaire than did antibiotic-treated patients with facial palsy. Thus, the overall current health status of each patient group was good, but sequelae were apparent primarily among patients with facial palsy who did not receive antibiotics for acute neuroborreliosis.

Adult↗
PubMed2000

HTLV-II and bacterial infections among injection drug users.

OBJECTIVE: To examine whether select bacterial infections are associated with HTLV-II infection among injection drug users, we conducted a nested case control study within an ongoing cohort study. METHOD: HTLV-II status was determined by enzyme-linked immunosorbent assay, immunofluorescent assay, and immunoblot. Diagnosis of bacterial pneumonia, infective endocarditis, and skin abscess was confirmed by standardized chart reviews. Three sets of cases were identified based on diagnosis of bacterial pneumonia, infective endocarditis validated by chart review, or self-reported skin abscess. Each case was matched to a minimum of 5 controls by age, HIV status, and study follow-up duration. Risk factors for each bacterial infection were analyzed separately by conditional logistic regression methods. RESULTS: Prevalence of HTLV-II infection ranged from 7% to 11% in cases and controls. The bivariate association of HTLV-II and bacterial pneumonia revealed an odds ratio (OR) of 1.1 (95% confidence interval [CI], 0.6-2.0); the association of infective endocarditis and HTLV-II revealed an OR of 1.7 (95% CI, 0. 7-3.9); and the association between HTLV-II and skin abscess revealed an OR of 1.3 (95% CI, 0.6-2.0). These ORs were unaltered by adjustment for other factors. CONCLUSION: Our results suggest that these three bacterial infections were not significantly associated with HTLV-II infection within a population of injection drug users. Additional associations between HTLV-II infection and disease outcomes merit further exploration.

Abscess↗
PubMed2000

Hypescheme: an operational criteria checklist and minimum data set for molecular genetic studies of attention deficit and hyperactivity disorders.

Investigators engaged in mapping the genetic basis of attention deficit hyperactivity disorder (ADHD) currently use a number of measures for the collection of clinical information. This gives rise to difficulties in comparing datasets and research communications between independent groups. This paper describes the development of Hypescheme, which is an operational criteria checklist for ADHD, oppositional defiant disorder (ODD), and conduct disorder (CD), and is proposed as a minimum dataset for those engaged in molecular genetic studies of ADHD. Hypescheme consists of a computerised data checklist system that includes all the operational criteria required for both DSM-IV and ICD-10 diagnostic criteria and a systematic record of information about comorbid psychiatric, developmental, and neurological disorders. Using this data, an algorithm applies both DSM-IV and ICD-10 criteria to generate operational diagnostics under both these systems. Hypescheme is not designed to replace current assessment protocols but to be a final common checklist that can be completed by experienced researchers using all available data.

Attention Deficit Disorder with Hyperactivity↗
PubMed2000

A natural history of hyperactivity and conduct problems: self-reported outcome.

At the age of 16-18 years, outcome was prospectively assessed in a general population sample of four behavioural groups, defined at 6-7 year old: a pure pervasively hyperactive group (N = 31), a mixed hyperactive conduct problem group (N = 20), a pure conduct problem group (N = 18) and a normal control group (N = 29). The objective of the present paper is to describe outcome in those domains for which self-report is recognised as a valid source of information. Differential effects for hyperactivity and conduct problems on outcome were studied. It was found that early hyperactivity and conduct problems predicted different patterns of conduct problems in adolescence. Drug use in adolescence was not predicted by either type of behavioural problem in childhood. Overall social adjustment was worse in the hyperactive groups, whereas no differences in self-esteem were found. Hyperactivity was a strong predictor of relationships problems in adolescence. The results suggest that hyperactivity and conduct problems in childhood are differential predictors of outcome in adolescence.

Adolescent↗
PubMed2000

Stimulant drugs.

Stimulants are a key element in the treatment of ADHD. Carefully designed trials of stimulants have found substantial improvement in ADHD core behaviours in 65-75 % of subjects with ADHD. Most standard stimulants are rapidly absorbed, with their behavioural effects appearing within 30 minutes, reaching a peak within one to three hours and disappearing within five hours. Doses at school are often necessary, in spite of the risk of peer ridicule and added adult supervision requirements. The mechanism by which stimulants act to reduce hyperactivity is not completely understood, but they improve impulsivity and activity levels. Several controlled evaluations made over periods of time greater than a year show a clear persistence of medication effects over time. A carefully crafted programme of treatment with methylphenidate is more effective in the reduction of hyperactivity symptoms than an intensive programme of behavioural and cognitive intervention. The combination of stimulants with psychosocial interventions in ADHD offers few advantages over medication alone. Unchallengeable guides to practice that would be appropriate everywhere are difficult to propose. It is imperative that clinicians prescribing stimulants should monitor the use of the drug properly, making sure that it is not being abused by the child's family, peers or those dispensing medication at school. Polypharmacy should only be embarked on by a specialist service and the combination of methylphenidate and clonidine should be used cautiously. Apart from ADHD, stimulants are useful in narcolepsy, resistant depression and partial syndromes of attention and hyperactivity. Major gaps in knowledge remain; pharmacokinetics, pharmacodynamics and pharmacogenetics of stimulant effects need further study. Details of stimulant administration regimes seem to have a major effect on the response achieved. Further research is needed, preferably in realistic practice settings, comparing different forms of combination with psychological interventions, investigating the effects in groups of children outside the core of schoolaged children with typical ADHD: preschool children, adults, those with partial syndromes (such as inattentiveness) and those with co-morbid disorders.

Adolescent↗
PubMed2000

Functional frontalisation with age: mapping neurodevelopmental trajectories with fMRI.

The aim of this study was to investigate whether previously observed hypofrontality in adolescents with attention deficit-hyperactivity disorder (ADHD) during executive functioning [Rubia K, Overmeyer S, Taylor E, Brammer M, Williams S, Simmons A, Andrew C, Bullmore ET. Hypofrontality in attention deficit hyperactivity disorder during higher order motor control: a study using fMRI. Am J Psychiatry 1999;156(6):891-896] could be attributed to delayed maturation of frontal cortex. Brain activation of 17 healthy subjects, 9 adolescents and 8 young adults, during performance of a motor response inhibition task and a motor timing task was measured using functional magnetic resonance imaging (fMRI). The effect of age on brain activation was estimated, using the analysis of variance and regression, at both voxel and regional levels. In the delay task, superior performance in adults was paralleled by a significantly increased power of response in a network comprising prefrontal and parietal cortical regions and putamen. In the stop task, alternative neuronal routes--left hemispheric prefrontal regions in adults and right hemispheric opercular frontal cortex and caudate in adolescents--seem to have been recruited by the two groups for achieving comparable performances. A significant age effect was found for the prefrontal activation in both task, confirming the hypothesis of a dysmaturational pathogenesis for the hypofrontality in ADHD.

Adolescent↗
PubMed2000

Corpus callosum may be similar in children with ADHD and siblings of children with ADHD.

No previous studies have used morphological neuroimaging to compare children with ADHD with siblings of children with ADHD. To test the hypothesis that the total size of the corpus callosum is altered in children with hyperkinetic disorder, the corpus callosum was outlined from a single midline protondensity weighted slice (containing the septum pellucidum). Fifteen boys with a refined phenotype of ADHD (mean age 10.2 years) and 15 healthy male siblings of children with ADHD (mean age 10.6 years) were enrolled in the study. The two groups were compared for global brain size and the callosal areas of Witelson. No significant differences were found between the study and comparison groups for any of the corpus callosum areas, even after age, global brain size, and handedness were covaried (using MANOVA). In addition, corpus callosum sizes do not seem to differ between children with ADHD and unaffected siblings of children with ADHD. Clinicians should not base their pathophysiological diagnosis of this disorder on an abnormality of callosal development.

Adolescent↗
PubMed2000

Factors affecting the risk of behaviour problems in children with severe intellectual disability.

In order to examine the importance of a range of potential risk factors for behaviour problems in children with severe intellectual disability, a sample was identified by the administration of a screening version of the Vineland Adaptive Behaviour Scales (VABS) to the parents of children aged 4-11 years attending six special needs schools in three adjacent inner London boroughs. Parents whose children had a VABS standard score of < or = 50 were interviewed using the Disability Assessment Schedule and both parents and teachers completed the Aberrant Behaviour Checklist. Most behaviour problems were more common in ambulant children, but problems less dependent on the ability to walk, such as sleeping difficulties, screaming and self-injury, were equally common in ambulant and non-ambulant children. Among ambulant children, there were few significant associations between the severity of the child's behaviour problems and the age or sex of the child, the presence or absence of epilepsy, and various indices of socio-economic disadvantage. Sleeping difficulties, overactivity, self-injury, destructive behaviour and autistic features, such as social withdrawal and stereotypies, were strongly associated with skills deficits, but aggression, temper tantrums and general disruptive behaviour were not. Limitations in daily living skills were better predictors of behaviour problems than were poor communication skills.

Child↗
PubMed2000

Analysis of the pattern of initiation of sustained ventricular arrhythmias in patients with implantable defibrillators.

INTRODUCTION: The purpose of this study was to analyze the pattern of initiation of sustained ventricular arrhythmias in patients with varying types of underlying structural heart disease. METHODS AND RESULTS: The study group consisted of 90 patients with an implantable cardioverter defibrillator. Cardiovascular diagnoses included coronary artery disease in 64 patients (71%). The patients were divided into four groups based on the type and severity of structural heart disease. Two hundred sixty episodes of sustained ventricular arrhythmias were analyzed. The mean coupling interval of the initiating beat of all ventricular arrhythmias was 523 +/- 171 msec. The coupling interval of the initiating beat was longer in patients with impaired ventricular function, particularly those with nonischemic dilated cardiomyopathy. The prematurity index was similar regardless of the type of underlying structural heart disease. However, the prematurity index was shorter in patients with polymorphic ventricular tachycardia (VT) compared to those with monomorphic VT. A pause was observed more commonly before the onset of polymorphic VT/ventricular fibrillation than sustained monomorphic VT. Two hundred twenty-two (85%) of the arrhythmia episodes were initiated by a late-coupled premature beat, 33 (13%) were initiated by an early-coupled premature beat, and 5 episodes (2%) were initiated with a short-long-short sequence. The pattern of initiation of the ventricular arrhythmias was similar in all patient groups and for both monomorphic and polymorphic tachycardias. CONCLUSION: These findings demonstrate that sustained ventricular arrhythmias typically are initiated by late-coupled ventricular premature depolarizations, regardless of the type or severity of underlying structural heart disease or resultant arrhythmia.

Adult↗