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Biomedical subjects

J Townsend

Publications and source records attributed to J Townsend.

At least 55 records · Page 3Linked to original sources
PubMed1999

Neuroanatomic contributions to slowed orienting of attention in children with autism.

Previous research has demonstrated that adult autistic patients are abnormally slow to orient attention, with degree of slowed orienting associated with severity of cerebellar hypoplasia. This research was extended to children who, at ages two through six, met diagnostic criteria for autism and underwent magnetic resonance imaging (MRI). An average of 3 years later, when old enough to participate in behavioral experiments, the children returned to the laboratory and completed a spatial attention paradigm. Degree of slowed attentional orienting to visual cues was significantly correlated with degree of cerebellar hypoplasia, but not with size of other neuroanatomic regions. Additionally, there was a trend for orienting speed to differ between diagnostic outcome subgroups; children with confirmed diagnoses of autism at time of behavioral testing had larger orienting deficits than those who no longer met diagnostic criteria for autism. This research is among the first to establish a specific brain-behavior link in autistic children.

Atrophy↗
PubMed1999

The role of general practice in promoting teenage health: a review of the literature.

BACKGROUND AND METHODS: Teenagers are acknowledged to be at high risk of health-damaging behaviours including smoking, teenage pregnancy, and drug and alcohol use. Additionally, the recognition of high levels of psychological distress is cause for serious concern about teenage health. This paper reviews health promotion interventions for teenagers in general practice. Medline, BIDS, Psyclit and SIGLE databases for January 1990-February 1997 were systematically searched for English language studies on adolescent/teenage health and health promotion interventions in primary health care/general practice; reference sections of articles were checked for earlier work. CONCLUSIONS: The literature indicates that teenagers rarely receive health promotion advice from their physicians. The impact on behaviour change, of screening and health promotion for teenagers in general practice requires further evaluation to asssess the potential effectiveness in preventing the onset or continuation of health-damaging behaviours.

Adolescent↗
PubMed1999

Primary care: past and future.

There is anecdotal evidence of a crisis in the recruitment and retention of general practitioners nationwide and particularly in inner cities. The relationship between quality of service and single-handed or group practice is uncertain and confounded by other aspects of practice structure and populations. The review examines the factors that influence doctors to enter and remain in general practice. It explores whether initiatives designed to address problems of recruitment and retention have been evaluated in the past and suggests how could they inform current initiatives.

Career Choice↗
PubMed1999

Shared care for high-dependency patients: mental illness, neurological disorders and terminal care--a review.

Changes in the structure of health services in the UK have increased the need to identify and formalize shared responsibilities between primary and secondary care for patients with chronic conditions. There are well-established schemes for the management of patients with some chronic diseases but very little for other high-dependency groups. This review examines the extent of systematic and shared care for some of the less well served groups: these are mental illness, neurological disorders and terminal care. Examples of good practice are highlighted.

Case Management↗
PubMed1999

Early brain proton magnetic resonance spectroscopy and neonatal neurology related to neurodevelopmental outcome at 1 year in term infants after presumed hypoxic-ischaemic brain injury.

This study investigated the accuracy of prediction of neurodevelopmental outcome at 1 year using cerebral proton magnetic resonance spectroscopy (MRS) and structured neonatal neurological assessment in term infants after presumed hypoxic-ischaemic brain injury. Eighteen control infants and 28 infants with presumed hypoxic-ischaemic brain injury underwent proton MRS investigation. Studies were carried out as soon as possible after the cerebral insult, most within 48 hours. Infants had an early structured neurological assessment at a median of 19 hours (range 0 hours to 9 days) from the presumed hypoxic-ischaemic insult and a late assessment at a median of 7 days (range 3 to 25 days) during recovery. The maximum cerebral peak-area ratio lactate:N-acetylaspartate measured by proton MRS accurately predicted adverse outcome at 1 year with a specificity of 93% and positive predictive value of 92%. Neurological assessment had a tendency for false-positive predictions. However, both early and late neurological examination can be used as a reliable indicator for a favourable outcome at 1 year having negative predictive values of 100% and 91% respectively.

Brain Ischemia↗
PubMed1998

Promoting adolescent mental health in primary care: a review of the literature.

High levels of psychological disturbance amongst adolescents have been linked to behaviours which can damage physical health, and with mental health problems in adulthood. The aim of this review was to see if published literature supports the hypothesis that primary care is a suitable setting in which mental health problems in adolescents can be prevented by early detection and treatment. Medline, BIDS, SIGLE and Psychlit databases (January 1990-February 1997) were systematically searched for English language studies on adolescent health promotion and mental health in primary care; reference sections were checked for earlier work. When offered, adolescent health checks and clinics have been well received with attendance rates of 73% and 83% reported, respectively. Primary care offers a setting for the prevention and detection of mental health problems in adolescents. Further research is needed to determine cost effective ways of using these opportunities.

Adolescent↗
PubMed1998

DR non-B1 mismatches influence allogeneic MLR-induced TH1- or TH2-like cytokine responses in rhesus monkeys.

Human and nonhuman primates have multiple DR B1 and non-B1 alleles. However, the role of mismatched DR non-B1 alleles in primary alloimmune responses is not well understood. Macaques, which share close DNA homologies with human MHC genes and have a high number of beta-chain genes in the DR subregion, are preeminent preclinical models for immunologic studies of transplant tolerance and immunosuppression. In this study, we examined the effect of allogeneic MHC Class II DRB mismatches in Th1- and Th2-like cytokine responses elicited in one-way MLR cultures in rhesus macaques. An ELISPOT method was used to estimate cytokine secretion at the single cell level. Molecular typing for DRB1 and DR non-B1 alleles was performed by a moderate-high resolution PCR-SSP method using a panel of 55 primer pairs covering 74 DRB alleles and clusters. Of 35 unrelated combinations, 66% had multiple (> or = 2) allelic MM at DRB1 and DR non-B1 with no significant correlation between numbers of DRB1 and DR non-B1 mismatches. Pairs with 1 or 0 MM were assigned to a mono/null MM group to obtain sufficient numbers for statistical analysis. The pairs differing by multiple vs. mono/null DRB1 MM showed no significant difference in cytokine prevalence (P = 0.69). In contrast, high IFN-gamma/ IL4 SFC ratios were noted in pairs with multiple vs. mono/null DR non-B1 MM (p = 0.0009). IFN-gamma/IL-10 spot forming cell (SFC) ratios were consistent with IFN-gamma/IL-4 SFC ratios (r = 0.98). Multiple DR non-B1 mismatches showed a trend towards higher MLR proliferative responses, although the stimulation index did not reflect the dominant cytokine response. These observations suggest a bias towards Th1-like cytokine production under allostimulation with multiple DR non-B1 gene products. Further study of the primary structure of DR non-B1 determinants may be helpful in understanding the fine molecular mechanisms governing the regulation of cytokine profiles during allostimulation in primates.

Animals↗
PubMed1998

The preliminary economic evaluation of health technologies for the prioritization of health technology assessments. A discussion.

This paper critically evaluates methods for the preliminary economic evaluation of health technologies and the prioritization of health technology assessment projects. It reports on the literature, and considers methods currently employed and the purposes of preliminary appraisal. It concludes that a preliminary economic appraisal needs to be applied to the two main stages of the prioritization process; to have transparent criteria; to allow for an appropriate range of potential outcomes; to be practicable, flexible, and efficient; and to be relevant to the assessment of different research projects.

Cost-Benefit Analysis↗
PubMed1998

Epilepsy in very preterm infants: neonatal cranial ultrasound reveals a high-risk subcategory.

The aim of this study was to investigate the association between epilepsy and perinatal brain injury in a cohort of 610 infants born preterm at <33 weeks' gestation. The prevalence of epilepsy in this cohort was 4.3% as determined by a postal questionnaire survey. Most children with epilepsy (16 of 24) had high-risk cranial ultrasound lesions including haemorrhagic parenchymal infarction (HPI), posthaemorrhagic hydrocephalus, and cystic periventricular leukomalacia (PVL). Of all the children in our cohort with high-risk brain lesions, those with epilepsy were more likely to have HPI and significantly less likely to have cystic PVL, although it is possible that PVL was not noticed in some cases. Children with epilepsy and high-risk cranial ultrasound lesions also showed more cognitive impairment than children with high-risk lesions but no epilepsy, which suggested more cortical grey-matter damage. We suggest that brain injury has occurred outside the confines of the periventricular white matter in this group of preterm infants with epilepsy.

Brain↗
PubMed1998

Hormone replacement therapy: assessment of present use, costs, and trends.

BACKGROUND: Hormone replacement therapy (HRT) is probably unprecedented as a drug in widespread preventive use by a predominantly well population, but there is little direct data on current trends in use. AIM: To estimate trends in the use and cost of HRT in Britain. METHOD: Government prescription data and therapy cost data were analysed to provide trends in costs and point prevalence of the use of HRT since 1980. Projections were estimated to the year 2000. RESULTS: In 1987, HRT was used by an estimated 2.2% of women aged 40 to 64 years in England, and by 1.0% in Scotland. By 1994 this had risen to 21.7% in England, 20.4% in Scotland, and 21.3% in Wales. Between 1980 and 1986, costs remained steady at approximately 11 million Pounds per annum for England and 1 million Pounds for Scotland (1994 values). Between 1987 and 1994 they rose to 87 million Pounds for England, 10 million Pounds for Scotland, and 46 million Pounds for Wales (1994 values). Projections suggest that, by the year 2000, 25.4% of women aged 40 to 64 years (95% CI = 20.1-30.7%) will be taking HRT at any one time, at a cost of 150 million Pounds (95% CI = 142 m Pounds-157 m Pounds: 1994 values). This implies an 'ever' user prevalence of at least two-thirds of women in this age group. CONCLUSION: Use of HRT for long-term therapy is widespread and rising. It is estimated that prevalence has increased tenfold since 1987. Average individual costs of therapy have fallen by one third. The level of reduced risk of osteoporosis and cardiovascular disease, and the balance with cost and potential increased risk of breast cancer, are not yet established and are in need of clarification.

Adult↗
PubMed1997

Community studies of the health service implications of low back pain.

STUDY DESIGN: Retrospective study using primary care physician case notes and a self-report questionnaire on the same randomly selected population sample. OBJECTIVES: To assess the prevalence, management, and outcomes of low back pain in the community, comparing, in the same random sample of registered patients, self-report questionnaire data and primary care physicians' records. SUMMARY OF BACKGROUND DATA: The financial and resource implications of low back pain are extensive. Data on consultations, investigations, and the management of low back pain are fragmentary and there are no comparisons estimating prevalence from case notes and self-report. METHODS: A retrospective study of prevalence, management, referral, and outcome covering the previous 12 months was carried out in three general practices using case notes and a self-report postal questionnaire on a sample of 900 patients over 18 years. RESULTS: Lifetime prevalence of low back pain was 62%. Annual prevalence was 48%, with 16% reporting low back pain at the time of report. Twenty-four percent consulted their primary care physician for low back pain, of whom 17% were referred to a hospital specialist. The annual consultation rate of patients with low back pain was similar to the rate for patients with chronic conditions. The activities of daily living were restricted in less than half, with few taking sick leave. The general health status of those reporting recent low back pain was significantly lower than those not reporting low back pain. Most felt that low back pain was self-limiting and would not consult health professionals for future episodes. There were substantial discrepancies between case notes recorded at consultation with the primary care physician and self-report regarding consultation and investigations. CONCLUSIONS: Prevalence rates were comparable with those reported in other studies. The significant discrepancies between data sources suggest patient recall bias or underrecording in case notes. The low consultation rate, time off, and day-to-day disability indicate that most episodes are self-limiting.

Adolescent↗
PubMed1997

Attention coordination and anticipatory control.

The coordination of the direction of selective attention is an adaptive function that may be one of the many anticipatory tools under cerebellar control. This chapter presents neurobehavioral, neurophysiological, and neuroimaging data to support our hypothesis that the cerebellum plays a role in attentional functions. We discuss the idea that the cerebellum is a master computational system that anticipates and adjusts responsiveness in a variety of brain systems (e.g., sensory, attention, memory, language, affect) to efficiently achieve goals determined by cerebral and other subcortical systems.

Adaptation, Physiological↗
PubMed1997

Cost effectiveness scenario analysis for a proposed trial of hormone replacement therapy.

Whereas evaluation of resource implications and quality of life are often incorporated into assessments of health technology, the decision to undertake the assessment is still mostly driven by interests in the clinical outcomes alone. A systematic approach to evaluating expected returns to health technology assessment has not been readily taken up by research funders or assessors. This paper sets out a specific methodology for ex ante evaluation or triage and proposes a decision procedure, using alternative outcome scenarios and the associated policy changes and costs and benefits, against a background of likely clinical practice in the absence of the assessment. The methodology is used to consider implications of a proposed major clinical trial to assess the long term costs and benefits of hormone replacement therapy.

Clinical Trials as Topic↗
PubMed1996

Visual attention abnormalities in autism: delayed orienting to location.

These studies provide evidence for slowed spatial orienting of attention in autism. A group of well-defined adult autistic subjects and age-matched normal controls performed a traditional spatial cueing task in which attention-related response facilitation is indexed by speed of target detection. To address the concern that motor impairment may interfere with interpretation of response time measures in those with neurologic abnormality, we also used a new adaptation of the traditional task that depended on accuracy of response (target discrimination) rather than speed of response. This design allowed separation of time to process and respond to target information from the time to move and engage (orient) attention. Results from both tasks were strikingly similar. Normal subjects oriented attention very quickly, and showed maximal performance facilitation at a cued location within 100 ms. Autistic subjects oriented attention much more slowly and showed increasing benefits of a spatial cue with increasing cue-to-target delays. These results are consistent with previous reports that patients with autism, the majority of whom have developmental abnormalities of the cerebellum, as well as those with acquired damage to the cerebellum, are slow to shift attention between and within modalities. This paper also addresses the variability in behavioral findings in autism, and suggests that many of the apparently contradictory findings may actually reflect sampling differences in patterns of brain pathology.

Adolescent↗
PubMed1996

Price and consumption of tobacco.

Progressive increases in cigarette tax rates provide a powerful contribution to policy for reducing cigarette consumption and generate extra government revenue. The policy has been most effective in groups for whom health publicity effects have been least so, but special provision may be necessary to avoid hardship to poor families.

Adolescent↗
PubMed1996

Stereotactic 14 gauge core-biopsy of the breast: results from 101 patients.

BACKGROUND: Along with fine needle aspiration (FNA) cytology, core-biopsy has become an integral part of the assessment of mammographically detected breast lesions. METHODS: A series of stereotactic large-core-biopsies of mammographically detected breast lesions was studied to assess the accuracy and limitations of the technique in diagnosing malignancy and in giving specific benign diagnoses, and its use in determining surgical management. RESULTS: Eighty per cent of carcinomas were diagnosed as malignant (absolute sensitivity). In 88.8% of the cancers, the core-biopsy was classified as malignant, suspicious or atypical/indeterminate (complete sensitivity), and in 72% of the invasive carcinomas, invasive tumour was present in the core. The technique was more successful for invasive carcinomas than for ductal carcinoma in situ (DCIS) (absolute sensitivity 86.1 and 55.5, respectively; P = 0.28) and for malignant mass lesions than for a mass with associated microcalcifications or for pure microcalcifications (absolute sensitivity 91, 71 and 66.6%, respectively; P = 0.19). In five of the 45 cancers (11.1%), no tumour tissue was present in the core, but all were excised after mammographic review and no delays in diagnosis have been experienced to date. The benign to malignant ratio for excised lesions was 0.11:1. Of the benign lesions, a specific diagnosis was given in 49% (calcifications in the core in a background of fibrocystic change, or postoperative scarring, or fibro-adenoma); the remainder showed non-specific benign findings. All patients where invasive carcinoma was diagnosed in the core underwent axillary clearance and wide local excision or mastectomy at their first operation. CONCLUSIONS: This technique can markedly reduce the number of benign lesions needing open biopsy, and provide information allowing definitive management of most carcinomas at the first operation. The accuracy of core-biopsy was lower in DCIS/microcalcification lesions; extra core samples or a combination of FNA and core-biopsy may be of value in these cases.

Biopsy↗