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Biomedical subjects

C Butler

Publications and source records attributed to C Butler.

At least 19 recordsLinked to original sources
PubMed1997

Multiplex sequencing of 1.5 Mb of the Mycobacterium leprae genome.

The nucleotide sequence of 1.5 Mb of genomic DNA from Mycobacterium leprae was determined using computer-assisted multiplex sequencing technology. This brings the 2.8-Mb M. leprae genome sequence to approximately 66% completion. The sequences, derived from 43 recombinant cosmids, contain 1046 putative protein-coding genes, 44 repetitive regions, 3 tRNAs, and 15 tRNAs. The gene density of one per 1.4 kb is slightly lower than that of Mycoplasma (1.2 kb). Of the protein coding genes, 44% have significant matches to genes with well-defined functions. Comparison of 1157 M. leprae and 1564 Mycobacterium tuberculosis proteins shows a complex mosaic of homologous genomic blocks with up to 22 adjacent proteins in conserved map order. Matches to known enzymatic, antigenic, membrane, cell wall, cell division, multidrug resistance, and virulence proteins suggest therapeutic and vaccine targets. Unusual features of the M. leprae genome include large polyketide synthase (pks) operons, inteins, and highly fragmented pseudogenes.

Amino Acid Sequence↗
PubMed1997

Incidence of childhood-onset IDDM in black African-heritage populations in the Caribbean. The Caribbean African Heritage IDDM Study (CAHIS) Group.

OBJECTIVE: To compare incidence rates of childhood-onset IDDM among black African-heritage populations age 0-19 years in the Caribbean region. RESEARCH DESIGN AND METHODS: Population-based registries for IDDM were established on the eastern Caribbean islands of Antigua, Barbados, Dominica, St. Croix, St. Kitts, St. Thomas, and Tortola using standardized criteria from the World Health Organization (WHO) Multinational Project for Childhood Diabetes (DiaMond). Average annual incidence rates (IR) with 95% CI for 0-19 years olds were computed using the DiaMond Registry program for the 5-year period from 1989 to 1993. Poisson regression analysis was used to determine differences in incidence rates. RESULTS: The highest incidence rate for 0-19 year olds was for the black African-heritage population of St. Croix (IR 10.09 per 100,000; 95% CI 4.35-19.89), one of the U.S. Caribbean islands. A significant (P < 0.05) 3.9 variation in IDDM incidence across the registries was found when the IR for St. Croix was compared to the IR for Barbados (IR 2.57 per 100,000; 95% CI 0.90-4.64). CONCLUSIONS: The variation in childhood-onset IDDM incidence rates among the black populations of the eastern Caribbean islands is consistent with the geographic variation in IDDM incidence seen among African Americans in the U.S. Variation in incidence rates of childhood diabetes in black populations may reflect differences in level of white genetic admixture or exposure to environmental diabetogenic agents.

Adolescent↗
PubMed1996

The practitioner, the patient and resistance to change: recent ideas on compliance.

Despite the explosion of research into the effect of medical advice on patient behaviour, only about 50% of patients comply with long-term drug regimens. And when it comes to changes in lifestyle, the percentage of patients who comply with medical advice often falls to single figures. Review articles on compliance have traditionally concentrated on factors that make it easier for patients to adhere to medical advice. However, recent articles urge clinicians to be more understanding of the wider implications of compliance in their patients' lives. This article focuses on how clinicians' consulting methods can affect patients' behaviour. Specifically, the authors consider the patient-centred clinical method as well as insights from and consulting techniques pioneered in the addictions field that can help to bring ambivalent patients closer to decisions about change. Instead of seeing resistance to change as rooted entirely in the patient, the authors view it as stemming partly from the way clinicians talk to patients. An advice-giving approach is usually inadequate to motivate people to embark on major lifestyle changes. Instead, the authors propose a negotiation-based framework that harnesses patients' intrinsic motivation to make their own decisions. This approach also promotes clinicians' acceptance of patients' decisions, even if these decisions run counter to current medical wisdom.

Attitude↗
PubMed1996

Novel effects of dendrotoxin homologues on subtypes of mammalian Kv1 potassium channels expressed in Xenopus oocytes.

We have examined the effects of two DTX homologues, toxin I and toxin K, on Kv1.1, Kv1.2 and Kv1.6 channels expressed in Xenopus oocytes. Toxin I blocked all three channels; in contrast, toxin K was selective for Kv1.1. Both toxins slowed channel activation and inactivation kinetics with 10 nM toxin I approximately doubling activation and inactivation time constants of Kv1.1. For the first time, we have demonstrated the selectivity of a DTX homologue for a single cloned Kv1 channel and suggest that these toxins may sterically hinder the conformational changes that occur during channel gating.

Animals↗
PubMed1996

Missing the meaning and provoking resistance; a case of myalgic encephalomyelitis.

BACKGROUND: The interaction between a clinician and a patient who put his problems down to myalgic encephalomyelitis is described. Despite attempting a patient-centred approach, the doctor acted on his own understanding of the meaning of this diagnosis without gaining proper insight into what it meant for the patient. This failure not only led to damaged rapport, it may have contributed to delayed recovery. OBJECTIVES: The unsatisfactory nature of this encounter led the clinician to consider more effective consulting techniques. METHODS AND RESULTS: A hypothetical interaction is constructed in which the clinician uses reflective listening statements to understand the patient's true meaning of this self-diagnosis. CONCLUSIONS: Despite well intentioned attempts to be patient-centered through widening the consultation beyond the biomedical to include personal and contextual factors, clinicians may still end up imposing their own medical meaning on patient's words. Damaged rapport is a signal that another track could be more fruitful and reflective listening is one strategy which enables clinicians to check that they fully understand the patient's meaning. Provoking resistance by following strategies which are not appropriate for the patient might then be avoided.

Absenteeism↗
PubMed1996

Design and analysis of studies evaluating smoking cessation interventions where effects vary between practices or practitioners.

BACKGROUND: Patients grouped together in practices may share characteristics that cause them to have similar responses to an intervention. Sampling from such groups means that the power of a trial is less than when subjects are selected from the population at random. Knowledge of likely variation in outcome at the practice level is necessary to calculate the extent to which sample size would need to be inflated to maintain statistical power in the face of 'cluster effects'. OBJECTIVES: To plan sample size and precision requirements of a clinical trial, we examined reports of primary care smoking cessation trials for information on outcomes at the level of clusters, and found them unhelpful. We therefore constructed hypothetical scenarios to quantity the potential importance of this effect. METHOD: Scenarios of moderate and large inter cluster variation were compared with a sample where there was no difference in effect size at the level of practices. RESULTS: A study with 80% power to detect a difference of 20% versus 10% at a 5% significance level would need 200 patients in each arm in the absence of cluster effects. With moderate variation in outcome between clusters, over a thousand patients would be needed in the study to maintain this precision. With larger inter-cluster variation, close to 4000 subjects would be required. CONCLUSIONS: In the absence of detailed data from previous studies, hypothetical models can give insight into the statistical implications of possible cluster effects on study design and analysis. With even moderate inter-cluster variation, sample size will have to be inflated considerably to maintain the same statistical precision. Workers in this field will greatly assist those planning future research if they publish details of variation in outcome at the level of clusters.

Chi-Square Distribution↗
PubMed1996

Late psychological sequelae of abortion: questions from a primary care perspective.

Research strongly supports the view that pregnancy termination is seldom associated with adverse psychological sequelae in the short to medium term, but experience shows that there is a small group of women who experience long and intense suffering. This is a report of the cases of two women who presented with psychological problems associated with a termination 19 and 5 years earlier.

Abortion, Induced↗
PubMed1995

Glycated haemoglobin and metabolic control of diabetes mellitus: external versus locally established clinical targets for primary care.

OBJECTIVES: To examine current targets for glycated haemoglobin as a marker for metabolic control in diabetes mellitus in relation to datasets from several areas, and to consider whether target setting could be improved. DESIGN: Data collected from enhanced care records of general practices for a representative community based sample of people with diabetes. SETTING AND SUBJECTS: 3022 people with diabetes on the lists of 37 general practices (total list size 222,550) in South Glamorgan in 1992; samples of glycated haemoglobin had been processed at two laboratories with different methodologies and reference ranges. MAIN OUTCOME MEASURES: Last glycated haemoglobin level measured in subjects for 1992 and published data from other studies considered in relation to existing goals and standards for the metabolic control of diabetes. RESULTS: An ascertainment rate for people with diabetes of 1.36% was obtained. The rate of data capture for haemoglobin A1 was 75.7%, and the mean level for study samples was 10.5% at one laboratory and 10.0% at the other (similar values to those of comparable studies). These mean levels of haemoglobin A1 in representative populations of people with diabetes are poor or very poor according to published standards, including those of the British Diabetic Association. These findings are set in the context of the psychology of goal setting and performance in complex clinical situations. CONCLUSION: Targets for clinical care that are set in the absence of normative data and local feasibility assessments should be treated with caution. Targets are more likely to enhance health care if target setters recognise the importance of psychological aspects of goal setting and motivation.

Biomarkers↗
PubMed1995

Outcomes that matter.

Explore the source record for details and available documents.

Persons with Disabilities↗
PubMed1994

Development of o.a.s.i.s., a new automated blood culture system in which detection is based on measurement of bottle headspace pressure changes.

o.a.s.i.s. (Unipath Ltd., Basingstoke, United Kingdom) is a new automated blood culture system. The metabolism of microorganisms is detected by measuring changes in the pressure of the headspace of blood culture bottles. These changes are measured by monitoring the position of a flexible sealing septum, every 5 min, with a scanning laser sensor. This noninvasive system can detect both gas absorption and production and does not rely solely on measuring increasing carbon dioxide levels. A research prototype instrument was used to carry out an evaluation of the media, the detection system, and its associated detection algorithm. In simulated blood cultures, o.a.s.i.s. supported growth and detected a range of clinical isolates. Times to positivity were significantly shorter in o.a.s.i.s. than in the BACTEC 460 system. Results of a clinical feasibility study, with a manual blood culture system as a control, confirmed that o.a.s.i.s. was able to support the growth and detection of a variety of clinically significant organisms. On the basis of these findings, full-scale comparative clinical trials of o.a.s.i.s. with other automated blood culture systems are warranted.

Adolescent↗
PubMed1994

Cavitary coccidioidomycosis with fungus ball formation. Diagnosis by fiberoptic bronchoscopy with coexistence of hyphae and spherules.

Pulmonary cavitary coccidioidomycosis with fungus ball formation was observed in two individuals with hemoptysis. The first patient had no overt compromise; the second was an insulin-dependent diabetic. In both, fiberoptic bronchoscopy was performed and cultures yielded Coccidioides immitis. The coexistence of spherules and hyphae of C immitis was seen histologically on bronchoscopic biopsy specimen of one cavitary lesion. Specific antifungal therapy and surgical excision were withheld and each patient has done well. This report provides for the first time nonsurgical confirmation that C immitis can produce an intracavitary fungus ball.

Adult↗