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Biomedical subjects

D Watson

Publications and source records attributed to D Watson.

At least 19 recordsLinked to original sources
PubMed2007

Listen to me, too! Lessons from involving children with complex healthcare needs in research about multi-agency services.

BACKGROUND: Children with complex healthcare needs are often excluded, both from active involvement in research projects and from direct consultation in services. During a 3-year research study into multi-agency services for children with complex healthcare needs, the authors involved children in a number of innovative ways and endeavoured to discover what impact, if any, multi-agency working made to them. METHODS: The researchers 'spent time' with 18 children with complex healthcare needs. They used a variety of methods to engage with the children in a meaningful way. More than half of the children had no verbal communication, so it was necessary in some cases to work with an advocate, usually the parent, to aid the process. RESULTS: Children with complex healthcare needs can take part in research as long as the research is set up sensitively and flexibly. In terms of the impact of multi-agency working, the authors concluded significant advances had been achieved for this group: almost all the children were living at home and attending school. However, there were significant gaps in addressing children's human rights in relation to communication, independence and relationships. In addition, many of the children had very little effective direct consultation with the multi-agency services. CONCLUSIONS: There are significant advances in involving disabled children in research and in service delivery, but there is still some way to go in involving those with complex healthcare needs. The challenges are considerable, but the benefits far outweigh these, not least being the value that parents, carers and the children themselves place upon being listened to.

Adolescent↗
PubMed2005

Changes in bacterial community structure correlate with initial operating conditions of a field-scale denitrifying fluidized bed reactor.

High levels of nitrate are present in groundwater migrating from the former waste disposal ponds at the Y-12 National Security Complex in Oak Ridge, TN. A field-scale denitrifying fluidized bed reactor (FBR) was designed, constructed, and operated with ethanol as an electron donor for the removal of nitrate. After inoculation, biofilms developed on the granular activated carbon particles. Changes in the bacterial community of the FBR were evaluated with clone libraries (n = 500 partial sequences) of the small-subunit rRNA gene for samples taken over a 4-month start-up period. Early phases of start-up operation were characterized by a period of selection, followed by low diversity and predominance by Azoarcus-like sequences. Possible explanations were high pH and nutrient limitations. After amelioration of these conditions, diversification increased rapidly, with the appearance of Dechloromonas, Pseudomonas, and Hydrogenophaga sequences. Changes in NO3, SO4, and pH also likely contributed to shifts in community composition. The detection of sulfate-reducing-bacteria-like sequences closely related to Desulfovibrio and Desulfuromonas in the FBR have important implications for downstream applications at the field site.

Bacteria↗
PubMed2005

The afterglow of GRB 050709 and the nature of the short-hard gamma-ray bursts.

The final chapter in the long-standing mystery of the gamma-ray bursts (GRBs) centres on the origin of the short-hard class of bursts, which are suspected on theoretical grounds to result from the coalescence of neutron-star or black-hole binary systems. Numerous searches for the afterglows of short-hard bursts have been made, galvanized by the revolution in our understanding of long-duration GRBs that followed the discovery in 1997 of their broadband (X-ray, optical and radio) afterglow emission. Here we present the discovery of the X-ray afterglow of a short-hard burst, GRB 050709, whose accurate position allows us to associate it unambiguously with a star-forming galaxy at redshift z = 0.160, and whose optical lightcurve definitively excludes a supernova association. Together with results from three other recent short-hard bursts, this suggests that short-hard bursts release much less energy than the long-duration GRBs. Models requiring young stellar populations, such as magnetars and collapsars, are ruled out, while coalescing degenerate binaries remain the most promising progenitor candidates.

Journal Article↗
PubMed2005

Digital mammography: a world without film?

OBJECTIVES: eDiaMoND is a next generation Internet ("Grid") multidisciplinary research project funded by the UK e-Science Programme with the following objectives; the development of a next generation Internet enabled prototype to demonstrate the potential benefits of a national infrastructure to support digital mammography; the exploration of potential benefits for digital mammography systems, with particular emphasis being placed on selected applications, namely, screening, training, computer-aided detection and appropriate support for epidemiological studies. METHODS: EDiaMoND has worked in conjunction with selected clinical partners to enable the collection of valuable mammography information and the design of applications based upon extensive requirements gathering exercises. The clinical partners validated both the immediate needs and assisted with defining future needs of such an architecture to support the UK Health Service. RESULTS: The project has succeeded in invoking the interest of clinical partners and representatives of the UK NHS Breast Screening Programme in our vision of a world without film, albeit a long way off. The project has also succeeded in identifying the barriers to adopting this approach with the current limitations within the NHS, and has developed a blueprint for working towards this strategy. CONCLUSIONS: A UK national digital mammography archive has the potential to provide major benefits for the UK. For example, such an archive could: ensure that previous mammograms are always available, and could link up seamlessly the screening, assessment and symptomatic clinics; it could provide a huge teaching and training resource; it could be a huge resource for epidemiological studies.

Archives↗
PubMed2004

Utilization of microbial biofilms as monitors of bioremediation.

A down-well aquifer microbial sampling system was developed using glass wool or Bio-Sep beads as a solid-phase support matrix. Here we describe the use of these devices to monitor the groundwater microbial community dynamics during field bioremediation experiments at the U.S. Department of Energy Natural and Accelerated Bioremediation Research Program's Field Research Center at the Oak Ridge National Laboratory. During the 6-week deployment, microbial biofilms colonized glass wool and bead internal surfaces. Changes in viable biomass, community composition, metabolic status, and respiratory state were reflected in sampler composition, type of donor, and groundwater pH. Biofilms that formed on Bio-Sep beads had 2-13 times greater viable biomass; however, the bead communities were less metabolically active [higher cyclopropane/monoenoic phospholipid fatty acid (PLFA) ratios] and had a lower aerobic respiratory state (lower total respiratory quinone/ PLFA ratio and ubiquinone/menaquinone ratio) than the biofilms formed on glass wool. Anaerobic growth in these systems was characterized by plasmalogen phospholipids and was greater in the wells that received electron donor additions. Partial 16S rDNA sequences indicated that Geobacter and nitrate-reducing organisms were induced by the acetate, ethanol, or glucose additions. DNA and lipid biomarkers were extracted and recovered without the complications that commonly plague sediment samples due to the presence of clay or dissolved organic matter. Although microbial community composition in the groundwater or adjacent sediments may differ from those formed on down-well biofilm samplers, the metabolic activity responses of the biofilms to modifications in groundwater geochemistry record the responses of the microbial community to biostimulation while providing integrative sampling and ease of recovery for biomarker analysis.

Acetates↗
PubMed2004

In situ bioreduction of technetium and uranium in a nitrate-contaminated aquifer.

The potential to stimulate an indigenous microbial community to reduce a mixture of U(VI) and Tc(VII) in the presence of high (120 mM) initial NO3- co-contamination was evaluated in a shallow unconfined aquifer using a series of single-well, push-pull tests. In the absence of added electron donor, NO3-, Tc(VII), and U(VI) reduction was not detectable. However, in the presence of added ethanol, glucose, or acetate to serve as electron donor, rapid NO3- utilization was observed. The accumulation of NO2-, the absence of detectable NH4+ accumulation, and the production of N2O during in situ acetylene-block experiments suggest that NO3- was being consumed via denitrification. Tc(VII) reduction occurred concurrently with NO3- reduction, but U(VI) reduction was not observed until two or more donor additions resulted in iron-reducing conditions, as detected by the production of Fe(II). Reoxidation/remobilization of U(IV) was also observed in tests conducted with high (approximately 120 mM) but not low (approximately 1 mM) initial NO3- concentrations and not during acetylene-block experiments conducted with high initial NO3-. These results suggest that NO3(-)-dependent microbial U(IV) oxidation may inhibit or reverse U(VI) reduction and decrease the stability of U(IV) in this environment. Changes in viable biomass, community composition, metabolic status, and respiratory state of organisms harvested from down-well microbial samplers deployed during these tests were consistent with the conclusions that electron donor additions resulted in microbial growth, the creation of anaerobic conditions, and an increase in activity of metal-reducing organisms (e.g., Geobacter). The results demonstrate that it is possible to stimulate the simultaneous bioreduction of U(VI) and Tc(VII) mixtures commonly found with NO3- co-contamination at radioactive waste sites.

Biodegradation, Environmental↗
PubMed2004

Managing chronic headaches in the clinic.

Chronic daily headache (CDH), which is often linked to a history of migraine, tension-type headache and the abuse of headache medications, and cluster headache are the best known of the chronic headaches. These headaches may not be well recognised or well treated in primary care. This article outlines the development of management algorithms for these headache subtypes, designed for use by the primary care physician with an interest in headache. Principles of care for chronic headaches include implementation of screening procedures, differential diagnosis, tailoring of management to the individual's needs, proactive follow-up and a team approach to care. These principles can be customised to the headache subtype by the selection of appropriate therapies. The optimal treatments for CDH include physical therapy to the neck if there is any stiffness there, withdrawal of abused medications and treatment of any subsequent withdrawal symptoms and headache prophylaxis, together with the provision of acute medications as rescue therapy. Optimal treatments for cluster headache include short- and long-term prophylaxis to prevent the headaches developing and acute medications for use as rescue. If treatment is ineffective, alternative medications can be provided at follow-up, with the possibility of referral for refractory patients.

Adolescent↗
PubMed2004

Effects of amisulpride, risperidone and chlorpromazine on auditory and visual latent inhibition, prepulse inhibition, executive function and eye movements in healthy volunteers.

In view of the evidence that cognitive deficits in schizophrenia are critically important for long-term outcome, it is essential to establish the effects that the various antipsychotic compounds have on cognition, particularly second-generation drugs. This parallel group, placebo-controlled study aimed to compare the effects in healthy volunteers (n = 128) of acute doses of the atypical antipsychotics amisulpride (300 mg) and risperidone (3 mg) to those of chlorpromazine (100 mg) on tests thought relevant to the schizophrenic process: auditory and visual latent inhibition, prepulse inhibition of the acoustic startle response, executive function and eye movements. The drugs tested were not found to affect auditory latent inhibition, prepulse inhibition or executive functioning as measured by the Cambridge Neuropsychological Test Battery and the FAS test of verbal fluency. However, risperidone disrupted and amisulpride showed a trend to disrupt visual latent inhibition. Although amisulpride did not affect eye movements, both risperidone and chlorpromazine decreased peak saccadic velocity and increased antisaccade error rates, which, in the risperidone group, correlated with drug-induced akathisia. It was concluded that single doses of these drugs appear to have little effect on cognition, but may affect eye movement parameters in accordance with the amount of sedation and akathisia they produce. The effect risperidone had on latent inhibition is likely to relate to its serotonergic properties. Furthermore, as the trend for disrupted visual latent inhibition following amisulpride was similar in nature to that which would be expected with amphetamine, it was concluded that its behaviour in this model is consistent with its preferential presynaptic dopamine antagonistic activity in low dose and its efficacy in the negative symptoms of schizophrenia.

Acoustic Stimulation↗
PubMed2004

Computer-enhanced insertion of the Oxford unicompartmental arthroplasty: a fluoroguide technique.

OBJECTIVE: To develop an accurate and reproducible technique for inserting Oxford Unicompartmental arthroplasties. MATERIALS AND METHODS: A protocol was developed to accurately position the femoral component of the Oxford Unicompartmental arthroplasty using computer-enhanced techniques. A dynamic reference body (DRB) is inserted into the femur, then antero-posterior (AP) and lateral fluoroscopic images are taken of the proximal femur. These images are digitized and entered into 3D space using a registered fluoroscopy machine. The femoral guide from the Oxford system is then placed on the medial femoral condyle in the standard manner. Holes are drilled directly towards the center of the femoral head using a registered drill. The femoral cuts are then made using the standard instruments from the Oxford set. RESULTS: This procedure was carried out on 15 sawbone femurs. Component position was determined by measuring radiographs after a trial component had been inserted. The average lateral error was 1.2 degrees (standard deviation [SD] = 1.207), compared to 4.1 degrees (SD = 2.875) with the standard technique. The average AP error was 2.5 degrees (SD = 1.767), compared to 5.1 degrees (SD = 2.219) with the standard technique. The differences in accuracy in both planes were statistically significant (p = 0.002 for AP, 0.001 for lateral). CONCLUSION: Using a Fluoroguide-assisted technique, we were able to insert the femoral component more precisely than when using the standard technique as described by the manufacturer.

Arthroplasty, Replacement, Knee↗
PubMed2002

The signature of supernova ejecta in the X-ray afterglow of the gamma-ray burst 011211.

Now that gamma-ray bursts (GRBs) have been determined to lie at cosmological distances, their isotropic burst energies are estimated to be as high as 1054 erg (ref. 2), making them the most energetic phenomena in the Universe. The nature of the progenitors responsible for the bursts remains, however, elusive. The favoured models range from the merger of two neutron stars in a binary system to the collapse of a massive star. Spectroscopic studies of the afterglow emission could reveal details of the environment of the burst, by indicating the elements present, the speed of the outflow and an estimate of the temperature. Here we report an X-ray spectrum of the afterglow of GRB011211, which shows emission lines of magnesium, silicon, sulphur, argon, calcium and possibly nickel, arising in metal-enriched material with an outflow velocity of the order of one-tenth the speed of light. These observations strongly favour models where a supernova explosion from a massive stellar progenitor precedes the burst event and is responsible for the outflowing matter.

Journal Article↗
PubMed2002

Personality testing and profiling for anaesthetic job recruitment: attitudes of anaesthetic specialists/consultants in New Zealand and Scotland.

Specialist/consultant anaesthetists based in New Zealand and Scotland were sent a reply paid postal questionnaire asking about their attitudes to personality testing and personality types in the recruitment process for registrars and specialists. The questionnaire consisted of nine Likert-style questions and 14 visual analogue questions. The overall response rate was 65% (523/808). The responses to all the questions were broadly similar in the two countries. Personality testing was deemed of use in recruiting trainees and specialists, with a slightly greater proportion considering personality traits more important than academic achievement. An overwhelming majority believed the presence of an adverse personality trait would influence an appointment process, but few believed that the personality makeup of anaesthetists influenced the way in which they react to stressful situations. A slight majority considered the interview process a poor predictor of personality. New Zealand anaesthetists rated independence, orderliness, compassion, empathy, reflectiveness and patience higher than did anaesthetists in Scotland. In contrast, anaesthetists in Scotland rated pragmatism, as opposed to perfection, as a more important characteristic than did the New Zealand specialists. Personality assessment, although not effective as the sole tool for candidate selection, may have a role in the process of anaesthetic job recruitment and warrants further investigation.

Anesthesiology↗
PubMed2002

Is being Aboriginal or Torres Strait Islander a risk factor for poor neonatal outcome in a tertiary referral unit in north Queensland?

OBJECTIVE: To compare perinatal outcomes for all births, and the morbidity and mortality patterns of babies admitted to neonatal intensive care, for non-Indigenous, Aboriginal and Torres Strait Islander (TSI) people in a major remote urban centre. METHODS: A prospective cohort study of all births and consecutive admissions to the Neonatal Intensive Care Unit/Special Baby Care Unit (NICU/SCBU) at Kirwan Hospital for Women (KWH), Townsville (a tertiary referral hospital) was conducted from January 1998 to June 1999. RESULTS: There were 2575 births, with 2392 (93%) booked into KWH for delivery. The Aboriginal group differed from the non-Indigenous group only in the prevalence of low-birthweight births. The TSI group had significantly higher perinatal mortality rates, preterm and low-birthweight births than the non-Indigenous group. Seven hundred and fifty-eight babies were admitted to NICU/SCBU: 586 (77%) non-Indigenous, 129 (17%) Aboriginal, 43 (6%) TSI. There were significantly more preterm, lower birthweight and longer stay length Aboriginal and TSI babies. Being Indigenous was not associated with neonatal death. Gestation of less than 28 weeks, congenital anomalies, and high-grade cerebral haemorrhage, but not ethnicity, were independent risk factors for neonatal death. Maternal risk factors, including poor antenatal care attendance, were more prevalent amongst Indigenous women. CONCLUSION: Neonatal outcomes for Aboriginal infants were better than expected from national and State reports. Outcomes for Torres Strait Islander infants were worse than expected. Ethnicity was not a risk factor for neonatal death. These findings suggest that outcomes may be further improved by programmes to increase access for Indigenous women to antenatal care services.

Adolescent↗
PubMed2002

Biochemical quantification of DNA in human articular and septal cartilage using PicoGreen and Hoechst 33258.

OBJECTIVE: To compare two fluorometric assays, utilizing (1) the bisbenzimidazole Hoechst 33258 and (2) PicoGreen, for determining DNA content in human cartilage. METHODS: Human articular and nasal septal cartilage explants were digested using proteinase K. Portions of sample digest were analysed for intrinsic and dye-enhanced fluorescence with either Hoechst 33258 or PicoGreen. RESULTS: Intrinsic tissue fluorescence in both articular and septal cartilage increased with age and was prominent at wavelengths used for Hoechst 33258 but relatively low at wavelengths used for PicoGreen. The relative contribution of intrinsic fluorescence to total dye-enhanced fluorescence of human cartilage was markedly greater for Hoechst 33258 (19-57%) than for PicoGreen (2-7%). Thus, in many situations, DNA in human cartilage can be assayed using PicoGreen without the need to correct for intrinsic cartilage fluorescence. The enhancement of fluorescence by each dye was found to be specific for DNA, as shown by fluorescence spectra, >90% sensitivity to DNase, and resistance to RNase. In addition, little or no interference was caused by non-DNA tissue components, since DNA caused an equal enhancement in the absence or presence of proteinase K digested human cartilage, once intrinsic cartilage fluorescence was subtracted. PicoGreen was more sensitive for assaying DNA (0.9ng DNA/ml) than Hoechst 33258 (6ng DNA/ml) and can also be used in a microplate reader. CONCLUSION: PicoGreen can be used in a rapid and sensitive assay to quantify DNA in small samples of human cartilage.

Adult↗
PubMed2002

Expression of T cell receptor variable region families by bone marrow gammadelta T cells in patients with IgA nephropathy.

IgA nephropathy (IgAN) is characterized by mesangial deposition of polymeric IgA (pIgA). Abnormalities of the IgA system include reduced mucosal and increased bone marrow (BM) pIgA production. Gammadelta T cells are regulators of mucosal IgA production and oral tolerance. We have described previously a deficiency of gammadelta T cells expressing Vgamma3 and Vdelta3 from the duodenal mucosa in IgAN. Since pIgA production is displaced to the BM, we have now studied BM gammadelta T cells in IgAN. Peripheral blood and BM aspirates were obtained from 14 patients with IgAN and 15 controls. Expression of TCR gamma and delta V region families was analysed by semiquantitative RT-PCR, and CDR3 spectratyping of Vgamma1-4 and Vdelta3 genes was performed. We found no difference between IgAN and controls in the V region usage of blood gammadelta T cells. However, in the BM of patients with IgAN, there was significantly reduced expression of the V region families Vgamma3 and Vdelta3, with the decrease in Vdelta3 being particularly striking. CDR3 spectratyping showed no abnormalities in blood or BM samples. Vgamma3 and Vdelta3 are underexpressed in the duodenum and the BM in IgAN. The combination of imbalanced mucosal and systemic pIgA production with deficient expression of gammadelta T cells using Vgamma3 and Vdelta3 in both sites may imply a role for these gammadelta T cells in the normal regulation of IgA immune responses, and in the complex immunopathogenesis of IgAN.

Adult↗
PubMed2002

Postnatal changes in maternal and neonatal plasma antioxidant vitamins and the influence of smoking.

OBJECTIVE: To study the postnatal changes in the plasma concentrations of fat soluble antioxidant vitamins and malondialdehyde (MDA) in mothers and their newborns and their relation to smoking. DESIGN: Prospective cohort study. SETTING: Tertiary perinatal centre. SUBJECTS: Eighteen non-smoking and 14 smoking mothers and 33 infants. MAIN OUTCOME MEASURES: Plasma concentrations of vitamins E, A, and beta-carotene and MDA were measured in mothers and infants at delivery and on day 4 post partum. RESULTS: Neonatal plasma levels of vitamins E, A, and beta-carotene were significantly lower than maternal levels both at delivery and on day 4 in both groups. There was a significant postnatal increase in plasma vitamin E levels in smoking mothers and neonates of both groups. A significant postnatal increase in maternal, but not neonatal, plasma vitamin A was noted in both groups. Cord plasma vitamin E levels were significantly lower in infants of smoking mothers (mean 4.7 v 6.5 micromol/l, p = 0.041). Plasma MDA was paradoxically lower in smoking mothers at delivery (3.19 v 4.01 micromol/l, p = 0.03) and on day 4 (1.37 v 3.29 micromol/l, p = 0.005) and in infants of the smoking group on day 4 (2.18 v 3.12 micromol/l, p = 0.014). Also, there was a significant postnatal fall in plasma MDA levels on day 4 in mothers and infants in the smoking group. CONCLUSIONS: The postnatal changes in plasma vitamin E were more pronounced in the smoking group. The postnatal changes in plasma vitamins A and beta-carotene were similar in both groups. The rapid decline in plasma MDA in smoking mothers and their infants suggests withdrawal of oxidative stress from smoking around delivery. This coincided with the increase in plasma vitamin E.

Adolescent↗
PubMed2002

Usage of triptans among migraine patients: an audit in nine GP practices.

A retrospective audit was carried out to investigate triptan usage over a period of one year among 360 adult patients with migraine in nine GP practices in the UK and the Republic of Ireland. Data from patient records were analysed, in conjunction with replies to a questionnaire about patients' perceptions of their migraine and its treatment. The majority of patients included in the audit were women (83%), and most patients (81%) were aged between 35 and 64 years. Most patients in the audit population (60%) were in the lowest band of triptan usage (1-36 tablets prescribed over 12 months); 7% had moderate usage (37-53 tablets). A minority of patients appeared to be taking triptans in higher quantities: about 15% of patients had been prescribed 54-94 triptan tablets over a year, 9% had received prescriptions for 95-149 tablets and 7% had received prescriptions for 150 or more tablets. These results indicated that some migraine patients were using triptans at higher than expected rates, and suggested that some patients might have been using their prescribed triptans inappropriately to treat a headache that they incorrectly perceived as migraine (e.g. chronic daily headache). Analyses were carried out to identify predictors of high usage. Predictors identified included the use of several other (non-triptan) medications to treat conditions other than migraine, one triptan dose being reported as sufficient to treat an attack, patient's perception of all headaches as migraine and lack of concern about taking too much medication. Patients identified as using triptans at a higher than expected rate can be called in for review of migraine diagnosis, identification of possible causes of any increased frequency of attacks, and investigation of suspected non-migrainous headaches, such as chronic daily headache and medication-induced headaches. For GPs, such actions would help achieve and maintain a high standard of care for their migraine patients, thus helping to contribute towards meeting the demands of the clinical governance agenda. Audit of triptan usage may also offer financial benefits for the practice, since helping patients to avoid the inappropriate use of triptans could lead to reductions in the overall costs of triptan prescribing within the practice. The high usage predictors could be developed into a checklist of potential indicators for GPs to identify patients who may become high users if prescribed triptans and who might require closer monitoring. We recommend that patients identified as having a potential for high usage should be routinely reviewed, every 3-6 months, to ensure that they are using triptans appropriately to treat migraine. Although triptans are generally safe and well tolerated, unnecessary use of any medication should be avoided.

Adolescent↗
PubMed2002

New guidelines for the management of migraine in primary care.

Despite repeated initiatives over the past decade, migraine remains under-recognised, under-diagnosed and under-treated in everyday clinical practice. The Migraine in Primary Care Advisors (MIPCA) group has produced new guidelines for migraine management to attempt to rectify this situation. MIPCA is a group of physicians, nurses, pharmacists and other healthcare professionals dedicated to the improvement of headache management in primary care, who have also worked closely with the Migraine Action Association (the UK patients' group) in the development of these guidelines. The principles of the new MIPCA guidelines are: To arrange specific consultations for headache. To institute a system of detailed history taking, patient education and buy-in at the outset of the consultation. To utilise a new screening algorithm for the differential diagnosis of headache, which can be confirmed by further questioning, if necessary. To institute a process of management that is individualised for each patient, using a new algorithm. Assessing the impact on the patient's daily life is a key aspect of diagnosis and management. To prescribe only treatments that have objective evidence of favourable efficacy and tolerability. To utilise prospective follow-up procedures to monitor the success of treatment. To organise a team approach to headache management in primary care.

Algorithms↗