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Biomedical subjects

S Lloyd

Publications and source records attributed to S Lloyd.

At least 19 recordsLinked to original sources
PubMed2007

Updated surgical experience with bone-anchored hearing aids in children.

BACKGROUND: We present the results of a retrospective review of children undergoing implantation with bone-anchored hearing aids (BAHAs) at the Great Ormond Street Hospital for Children. METHODS: The case notes of 71 children undergoing BAHA placement at the Great Ormond Street Hospital for Children between December 1990 and August 2002 were reviewed. Outcome measures included hearing thresholds, incidence of fixture loss, skin reaction and need for revision. Quality of life outcomes were also measured. RESULTS: Eighty-five ears had been implanted. Fifty-four per cent of children had experienced no complications, 42 per cent had required revision surgery and 26 per cent had experienced fixture loss at some point. Young age at implantation was associated with an adverse outcome. Trauma and failure of osseointegration had been the commonest reasons for failure. A skin reaction around the abutment had occurred at some point in 37 per cent of children but had persisted for longer than six months in only 9 per cent; this had been associated with fixture loss. The use of fixture site split skin grafts had reduced problems with skin hypertrophy and hair overgrowth. Hearing thresholds when using BAHAs had been comparable to those when using bone conduction hearing aids. However, BAHAs had significant additional benefits in terms of sound quality, ease of use and overall quality of life. CONCLUSION: Bone-anchored hearing aids provide significant benefits over other types of hearing aid, both audiologically and in terms of quality of life. Careful selection of candidates and meticulous follow up are required in order to minimize complications.

Adolescent↗
PubMed2006

Simple keel fixation technique for endoscopic repair of anterior glottic stenosis.

The use of keels in the treatment of anterior glottic stenosis is well established. A variety of methods for keel fixation have previously been documented. We describe a simple technique of securing a Silastic keel, placed endoscopically, with a simple percutaneous suture, after laser vaporization of an anterior commissure web.

Aged↗
PubMed2006

Haematology and biochemistry in healthy young pheasants and red-legged partridges and effects of spironucleosis on these parameters.

Plasma biochemical and haematological parameters were examined in 4-week-old to 12-week-old game birds. Healthy, uninfected pheasants and partridges had similar levels of total protein, albumin, osmolality, Na+, Cl-, K+, Mg2+ and glucose. Triglyceride, globulin and Ca2+ were significantly higher and PO43- was lower in the partridges. Pheasants carrying a light to moderate infection with Spironucleus had significantly lower total protein, albumin, osmolality, Na+, Cl-, Ca2+ and PO43-. In severely affected pheasants, the osmolality, Na+ and Cl- fell further. Triglyceride and glucose were significantly lower than in healthy birds, and Mg2+ was higher. Similar data were obtained from infected partridges. Red cell parameters rose significantly in pheasants severely affected by spironucleosis, and the percent of heterophils was significantly higher and lymphocytes and basophils lower in their blood smears. The breast and leg muscle wet weight from severely affected pheasants was 22.2 and 37.7% that of uninfected birds, although the water content of the breast muscle was significantly higher.

Animals↗
PubMed2006

The association between domestic violence and self harm in emergency medicine patients.

AIMS: This study compared rates of self harm among victims of domestic assault presenting to an emergency department (ED) with those rates among other ED patients. It also explored the temporal and numeric relation between domestic assaults and self harm. METHODS: A retrospective matched cohort study was conducted using the medical records of a single ED. The cases were patients who had presented to the ED as a consequence of domestic assault. Two control groups matched for age, sex, and Cambridge postcode were randomly generated from the ED patient list. The second control group cases were also matched for postcode sector as a surrogate approximate for socioeconomic status in addition to age and sex. Cases and controls were followed up between November 1996 and 1 October 2004 documenting the number and timing of episodes of self harm reported in the study period. RESULTS: Altogether, 294 cases and 558 controls were followed up. Patients suffering domestic assault were more likely to present with self harm than controls (RR 3.6 95% CI 2.1-6.5). This effect appeared to be independent of deprivation. Patients suffering domestic assault had more ED contacts than controls. There was a moderate correlation between the number of episodes of self harm and number of assaults (Spearman's rho 0.3 p<0.001). Socioeconomic status was a poor predictor of self harm. Emergency physicians should consider asking about suicidal ideation in victims of domestic assault.

Adult↗
PubMed2005

Towards a Grid infrastructure to support integrative approaches to biological research.

This paper discusses the scientific rationale behind the e-Science project, Integrative Biology, which is developing mathematical modelling tools, HPC-enabled simulations and an underpinning Grid infrastructure to provide an integrative approach to the modelling of complex biological systems. The project is focusing on two key applications to validate the approach: the modelling of heart disease and cancer, which together are responsible for over 60% of deaths in the United Kingdom. This paper provides an overview of the project, describes the initial prototype architecture and discusses the long-term scientific aims.

Biology↗
PubMed2005

Entanglement assisted metrology.

We propose a new approach to the measurement of a single spin state, based on nuclear magnetic resonance (NMR) techniques and inspired by the coherent control over many-body systems envisaged by quantum information processing. A single target spin is coupled via the magnetic dipolar interaction to a large ensemble of spins. Applying radio frequency pulses, we can control the evolution so that the spin ensemble reaches one of two orthogonal states whose collective properties differ depending on the state of the target spin and are easily measured. We first describe this measurement process using quantum gates; then we show how equivalent schemes can be defined in terms of the Hamiltonian and thus implemented under conditions of real control, using well established NMR techniques. We demonstrate this method with a proof of principle experiment in ensemble liquid state NMR and simulations for small spin systems.

Journal Article↗
PubMed2005

Fluid absorption in the small intestine of healthy game birds and those infected with Spironucleus spp.

Absorption of fluid by the small intestine of 4-week-old to 12-week-old farmed pheasants and partridges has been studied using an inverted sac technique. The mean rate of absorption was 54 +/- 4 (mean +/- standard error of the mean) microl/g dry tissue/min in pheasants and 49 +/- 3 microl/g dry tissue/min in partridges. Use of inhibitors and ion substitution suggested transepithelial transport driven by baso-lateral Na+/K+ pumps, in combination with mucosal Na+-coupled transporters, including Cl(-)-coupled transporters. Absorption was more than halved to 17 +/- 2 microl/g dry tissue/min (P < 0.001) in birds that were very heavily infected with Spironucleus spp. in their small intestine and showing a syndrome of diarrhoea, depression and loss of weight to severe emaciation. Birds carrying light to moderate levels of infection with Spironucleus had very variable rates of absorption that were statistically similar to the controls. Doubling the glucose concentration in the buffer to 40 mM significantly enhanced absorption.

Animals↗
PubMed2005

Detection of quantitative trait loci for androstenone, skatole and boar taint in a cross between Large White and Meishan pigs.

'Boar taint' is a strong perspiration-like, urine-like unpleasant odour given off upon heating or cooking of meat from some intact (uncastrated) male pigs. Data from the F(2) generation of a Large White (LW) x Meishan (MS) crossbred population were analysed to detect quantitative trait loci (QTL) for traits associated with boar taint. Fat samples from 178 intact male pigs slaughtered at 85 +/- 5 kg were analysed for the major contributors to boar taint (androstenone, indole and skatole). Fat and lean samples from cooked meat were scored for boar, abnormal and pork flavour and odour by a trained sensory panel (SP). A scan with 117 markers covering the whole genome was performed in the F(2) individuals, together with their F(1) parents and purebred grandparents. At the 5% chromosomal significance threshold (approximately equal to the genome-wide suggestive significance threshold), QTL were detected for the laboratory estimate of androstenone on chromosomes 2, 4, 6, 7 and 9. However, only on chromosome 6 were there QTL for boar flavour (BF) traits in the same or adjacent marker intervals as a QTL for the laboratory estimate of androstenone. On chromosome 14, QTL were detected for the laboratory estimates of indole and skatole, the SP score for skatole and the scores for BF in lean and BF in fat. In all five cases, the MS allele generally increased the estimate or score, compared with the LW allele, but it appeared that desirable and undesirable alleles were present in both breeds. This locus on chromosome 14 has considerable potential for use to reduce the incidence of boar taint, especially if further research can identify the causative polymorphism or strongly associated markers.

Androsterone↗
PubMed2005

The Healthgrid White Paper.

Over the last four years, a community of researchers working on Grid and High Performance Computing technologies started discussing the barriers and opportunities that grid technologies must face and exploit for the development of health-related applications. This interest lead to the first Healthgrid conference, held in Lyon, France, on January 16th-17th, 2003, with the focus of creating increased awareness about the possibilities and advantages linked to the deployment of grid technologies in health, ultimately targeting the creation of a European/international grid infrastructure for health. The topics of this conference converged with the position of the eHealth division of the European Commission, whose mandate from the Lisbon Meeting was "To develop an intelligent environment that enables ubiquitous management of citizens' health status, and to assist health professionals in coping with some major challenges, risk management and the integration into clinical practice of advances in health knowledge." In this context "Health" involves not only clinical procedures but covers the whole range of information from molecular level (genetic and proteomic information) over cells and tissues, to the individual and finally the population level (social healthcare). Grid technology offers the opportunity to create a common working backbone for all different members of this large "health family" and will hopefully lead to an increased awareness and interoperability among disciplines. The first HealthGrid conference led to the creation of the Healthgrid association, a non-profit research association legally incorporated in France but formed from the broad community of European researchers and institutions sharing expertise in health grids. After the second Healthgrid conference, held in Clermont-Ferrand on January 29th-30th, 2004, the need for a "white paper" on the current status and prospective of health grids was raised. Over fifty experts from different areas of grid technologies, eHealth applications and the medical world were invited to contribute to the preparation of this document.

Computer Communication Networks↗
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↗
PubMed2005

Security aspects of Grid-based digital mammography.

OBJECTIVES: The principal aim of the eDiaMoND project is to develop a prototype Grid infrastructure to support the needs of the breast care community. The prototype system is but one major deliverable of the project; the other is a blueprint document that describes how a system such as eDiaMoND might be deployed throughout the United Kingdom to support the NHS Breast Screening Programme. A key consideration of both the prototype and the blueprint is security. In this paper we address some of the generic security issues faced by projects such as eDiaMoND. We also indicate how these problems are being overcome within our project. METHODS: In order to fully understand the security issues faced by the project a review of current initiatives within the NHS was performed. The work of the NHS Information Authority was found to be particularly significant. Also reviewed was BS7799, the British Standard for the deployment of security systems and processes. Finally, modelling of the proposed prototype was performed using methods proposed by the e-Science Security Task Force, in particular the method proposed by Flechais and Sasse. RESULTS AND CONCLUSIONS: It is felt that the issues of security surrounding the eDiaMoND project are sufficiently generic that the eHealth community can consider and criticise the work described. It is hoped that this will enable the eHealth community to move forwards with a common agenda.

Access to Information↗
PubMed2004

Classical capacity of the lossy bosonic channel: the exact solution.

The classical capacity of the lossy bosonic channel is calculated exactly. It is shown that its Holevo information is not superadditive, and that a coherent-state encoding achieves capacity. The capacity of far-field, free-space optical communications is given as an example.

Journal Article↗
PubMed2004

Glomus jugulare tumour presenting with isolated accessory nerve palsy.

Glomus tumours of the skull base are rare, and most frequently present with symptoms of hearing loss and tinnitus. Diagnosis is often delayed due to the slow growth of the tumour. We describe the previously unreported occurrence of a glomus tumour presenting with a unilateral accessory nerve palsy.

Accessory Nerve Diseases↗
PubMed2004

Computer-assisted total knee replacement. A controlled cadaver study using a multi-parameter quantitative CT assessment of alignment (the Perth CT Protocol).

A controlled study, comparing computer- and conventional jig-assisted total knee replacement in six cadavers is presented. In order to provide a quantitative assessment of the alignment of the replacements, a CT-based technique which measures seven parameters of alignment has been devised and used. In this a multi-slice CT machine scanned in 2.5 mm slices from the acetabular roof to the dome of the talus with the subject's legs held in a standard position. The mechanical and anatomical axes were identified, from three-dimensional landmarks, in both anteroposterior and lateral planes. The coronal and sagittal alignment of the prosthesis was then measured against the axes. The rotation of the femoral component was measured relative to the transepicondylar axis. The rotation of the tibial component was measured with reference to the posterior tibial condyles and the tibial tuberosity. Coupled femorotibial rotational alignment was assessed by superimposition of the femoral and tibial axial images. The radiation dose was 2.7 mSV. The computer-assisted total knee replacements showed better alignment in rotation and flexion of the femoral component, the posterior slope of the tibial component and in the matching of the femoral and tibial components in rotation. Differences were statistically significant and of a magnitude that support extension of computer assistance to the clinical situation.

Arthroplasty, Replacement, Knee↗
PubMed2003

Quality of life of patients undergoing surgical treatment of head and neck malignancy.

This study prospectively follows changes in quality of life (QoL) of 40 patients undergoing surgical treatment for head and neck malignancy over a 1-year period, using the University of Washington QoL questionnaire version 4.0. The tumour types included oral, oropharyngeal, hypopharyngeal, oesophageal, laryngeal, sinonasal and thyroid carcinomas. Mean overall QoL scores were significantly worse at 3 and 6 months (P < 0.05) and returned to around preoperative scores at 12 months (P = 0.11). Oropharyngeal, laryngeal, sinonasal and thyroid subsites all maintained QoL scores at each time point. QoL scores for hypopharyngeal and oral subsites dropped markedly at 3 and 6 months but returned to around preoperative levels at 12 months. The domains most affected by treatment varied depending on tumour subsite. For the population as a whole, their appearance, activity, speech, shoulder and saliva domains were all significantly less at 12 months. Anxiety scores were significantly better at 12 months.

Aged↗
PubMed2002

Control of Echinococcus granulosus in Uruguay: evaluation of different treatment intervals for dogs.

This study attempted control of transmission of Echinococcus granulosus from dogs to sheep in different areas in the Department of Florida, Uruguay, by treating dogs with praziquantel at intervals of 6, 12 and 16 weeks. The 6-week interval was based on the prepatent period of infection with E. granulosus, the 12- and 16-week intervals were based on the rate of reinfection with tapeworms in dogs in the area. Dogs had become reinfected with E. granulosus between 2 and 4 months after treatment, whereas they became reinfected with the Taenia spp. tapeworms within 2 months of treatment. One year after the start of treatments sentinel lambs were born and grazed the farms in the three treatment areas. Approximately, 15 months later when the sentinel lambs were killed and examined for parasites the six weekly treatments had stopped the transmission of E. granulosus to the sentinel lambs. Treatment of dogs at 12- and 16-week intervals failed to stop transmission of E. granulosus but both the numbers of farms and the numbers of sheep infected with E. granulosus were lower where dogs received 12 weekly treatments compared with dogs receiving 16 weekly treatments and a fourth area where dogs had received no treatments (chi(2)P=0.002). Lambs continued to become infected with the Taenia spp. tapeworms in all the areas. Control was complicated by large changes in the dog population. From a starting population of 1164 dogs in the three treated areas, 832 new dogs, most of these adult hunting dogs, entered the population and 793 dogs were lost from the population.

Animals↗