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P Taylor

Publications and source records attributed to P Taylor.

At least 37 records · Page 2Linked to original sources
PubMed2004

Elicitation and representation of expert knowledge for computer aided diagnosis in mammography.

OBJECTIVES: To study how professional radiologists describe, interpret and make decisions about micro-calcifications in mammograms. The purpose was to develop a model of the radiologists' decision making for use in CADMIUM II, a computerized aid for mammogram interpretation that combines symbolic reasoning with image processing. METHODS: In Study 1, eleven radiologists were asked to 'think out loud' as they interpreted 20 sets of calcifications. Participants used 159 terms to describe calcifications. We used these data to design a scheme with 50 descriptors. In Study 2, ten radiologists used the scheme to describe 40 sets of calcifications. We assessed the capacity of the terms to discriminate between benign and malignant calcifications, testing them against radiologists' assessments of malignancy and follow-up data. RESULTS: The descriptors that were found to be the most discriminating in Study 2 were included in CADIMUM II's knowledge base. They were represented as arguments for either a benign or a malignant diagnosis. These arguments are the central component of the decision support provided by the system. Other components are: image processing algorithms for the detection and measurement of calcifications and a set of rules that use the measures to decide which of the arguments apply to a given set of calcifications. CONCLUSIONS: Preliminary evaluations of the CADMIUM II prototype reinforce the value of representing explicitly decision making processes in computer aided mammography and of deriving these processes from image processing measurements. Decision support is presented here at a level of description that is both relevant and meaningful to the user.

Algorithms↗
PubMed2003

Ostwald ripening in emulsions: estimation of solution thermodynamics of the disperse phase.

The rate of Ostwald ripening has been measured for small emulsions prepared by the dilution of O/W microemulsions containing a range of n-alkanes. The rates were determined as a function of temperature for decane, undecane, dodecane and tri-decane using photon correlation spectroscopy. The aqueous solubilities of these oils were estimated from the rates of ripening using the Lifshitz, Slyozov and Wagner theory of Ostwald ripening. These solubilities were used to calculate the free energy, enthalpy and entropy of solution for the 4 alkanes. Values obtained were in good agreement with literature values. The free energy of solution of hexadecane and octadecane were also determined from the rate of ripening of mixed oil phase emulsions with dodecane using the treatment suggested by Kabalnov. The values obtained agreed well with extrapolated values of the free energy from lower alkanes, suggesting that coiling or aggregation of the longer chain molecules in solution was not affecting the solubility.

Journal Article↗
PubMed2003

Determination of tributyltin in marine sediment: Comité Consultatif pour la Quantité de Matière (CCQM) pilot study P-18 international intercomparison.

The capabilities of National Metrology Institutes (NMIs-those which are members of the Comité Consultatif pour la Quantité de Matière (CCQM)of the CIPM) and selected outside "expert" laboratories to quantitate (C(4)H(9))(3)Sn(+) (TBT) in a prepared marine sediment were assessed. This exercise was sanctioned by the 7th CCQM meeting, April 4-6, 2001, as an activity of the Inorganic Analysis Working Group and was jointly piloted by the Institute for National Measurement Standards of the National Research Council of Canada (NRC) and the Laboratory of the Government Chemist (LGC), UK. A total of 11 laboratories submitted results (7 NMIs, and 4 external labs). Two external laboratories utilized a standard calibration approach based on a natural abundance TBT standard, whereas all NMIs relied upon isotope dilution mass spectrometry for quantitation. For this purpose, a species specific (117)Sn-enriched TBT standard was supplied by the LGC. No sample preparation methodology was prescribed by the piloting laboratories and, by consequence, a variety of approaches was adopted by the participants, including mechanical shaking, sonication, accelerated solvent extraction, microwave assisted extraction and heating in combination with Grignard derivatization, ethylation and direct sampling. Detection techniques included ICP-MS (with GC and HPLC sample introduction), GC-MS, GC-AED and GC-FPD. Recovery of TBT from a control standard (NRCC CRM PACS-2 marine sediment) averaged 93.5+/-2.4% ( n=14). Results for the pilot material averaged 0.680+/-0.015 micro mol kg(-1) ( n=14; 80.7+/-1.8 micro g kg(-1)) with a median value of 0.676 micro mol kg(-1). Overall, performance was substantially better than state-of-the-art expectations and the satisfactory agreement amongst participants permitted scheduling of a follow-up Key comparison for TBT (K-28), a Pilot intercomparison for DBT (P-43), and certification of the test sediment for TBT content and its release as a new Certified Reference Material (HIPA-1) with a TBT content of 0.679+/-0.089 micro mol kg(-1) (expanded uncertainty, k=2, as Sn) (80.5+/-10.6 micro g kg(-1)).

Journal Article↗
PubMed2003

Aid to the antemortem diagnosis of Fell pony foal syndrome by the analysis of B lymphocytes.

Fell pony foals are affected by a congenital fatal immunodeficiency that commonly leads to anaemia and lymphopenia. Previous work has shown that the foals' circulating subpopulations of CD4 and CD8 T lymphocytes are unaffected. In this study it was shown that the mean population of B lymphocytes in 10 affected foals was less than 10 per cent of that in normal foals.

Animals↗
PubMed2003

PRINTS and its automatic supplement, prePRINTS.

The PRINTS database houses a collection of protein fingerprints. These may be used to assign uncharacterised sequences to known families and hence to infer tentative functions. The September 2002 release (version 36.0) includes 1800 fingerprints, encoding approximately 11 000 motifs, covering a range of globular and membrane proteins, modular polypeptides and so on. In addition to its continued steady growth, we report here the development of an automatic supplement, prePRINTS, designed to increase the coverage of the resource and reduce some of the manual burdens inherent in its maintenance. The databases are accessible for interrogation and searching at http://www.bioinf.man.ac.uk/dbbrowser/PRINTS/.

Amino Acid Motifs↗
PubMed2003

Reproducibility of prompts in computer-aided detection (CAD) of breast cancer.

AIM: We evaluated the reproducibility of prompts using the R2 ImageChecker M2000 computer-aided detection (CAD) system. MATERIALS AND METHODS: Forty selected two-view mammograms of women with breast cancer were digitized and analysed using the ImageChecker on 10 separate occasions. The mammograms were chosen to provide both straightforward and subtle signs of malignancy. Data analysed included mammographic abnormality, pathology, and whether the cancer was prompted or given an emphasized prompt. RESULTS: Correct prompts were generated in 86 out of 100 occasions for screen-detected cancers. Reproducibility was less in the other categories of more subtle cancers: 21% for cancers previously missed by CAD, a group that contained more grade 1 and small (<10 mm) tumours. Prompts for calcifications were more reproducible than those for masses (76% versus 53%) and these cancers were more likely to have an emphasized prompt. CONCLUSIONS: Probably the most important cause of variability of prompts is shifts in film position between sequential digitizations. Consequently subtle lesions that are only just above the threshold for display may not be prompted on repeat scanning. However, users of CAD should be aware that even emphasized prompts are not consistently reproducible.

Breast Neoplasms↗
PubMed2003

An outbreak of hepatitis A associated with consumption of raw blueberries.

This report describes the epidemiology, investigation and control of a hepatitis A (HAV) outbreak in New Zealand. Descriptive and analytical epidemiology, virology, product traceback and an orchard investigation were carried out. A case-control study revealed that 56% of 39 cases had consumed raw blueberries, compared with 14% of 71 controls (odds ratio 7.6; 95% confidence intervals 2.6-22.4). Traceback of product through retailers and wholesalers implicated a single commercial orchard. Hepatitis A virus was detected by reverse transcriptase polymerase chain reaction in faecal specimens from cases as well as a blueberry product from the orchard. Presence of hepatitis A virus was confirmed by DNA hybridization and sequencing of PCR products. Sanitary audit of the orchard revealed multiple opportunities for contamination of blueberries by pickers. This outbreak highlights the need for food safety programmes in the berry fruit industry.

Adolescent↗
PubMed2003

Outcome of 27 patients with Hurler's syndrome transplanted from either related or unrelated haematopoietic stem cell sources.

Over the last 15 years, we have performed a total of 30 haematopoietic stem cell transplants on 27 children suffering from Hurler's syndrome. These children were of median age 11 months at the time of diagnosis and 25 months at the time of transplantation. The phenotype was severe in 21 cases (78%). The donor was familial in 13 cases: nine genotypically identical, one phenotypically identical father and three HLA-mismatched donors. Unrelated donors were selected in 17 cases: four phenotypically identical and 13 with 1-4 HLA mismatches. The conditioning regimen generally consisted of busulphan 600 mg/m(2) plus cyclophosphamide (Endoxan) 260 mg/kg and cyclosporin with methotrexate for GvHD prophylaxis. Rabbit anti-thymocyte globulin (Thymoglobuline) was given for all unrelated or familial mismatched transplantations. The median nucleated cell dose infused was 6.00 x 10(8) TNC/kg. No bone marrow (apart from one) was T cell depleted. For first transplants, engraftment was observed in 23/27 patients (pts) (85%). Primary graft failure was observed in 4/27 patients (16%), two were retransplanted from an unrelated donor, one with success. Four patients have died. The primary cause of death was infection in three cases (TRM : 11%) and disease progression in one case, after primary graft failure. Of the 23 living patients, two have disease progression after graft failure and 21 (78%) have functional grafts with a favourable long-term outcome after a median follow-up of 4.7 years, having either full or mixed chimaerism. Among surviving patients with functional grafts, 13 (62%) were transplanted from unrelated donors of whom 10 (77 %) had HLA disparities. There was a remarkably low incidence of GvHD. In our experience, haematopoietic stem cell transplantation using an HLA-matched familial donor or an HLA-matched or -mismatched unrelated donor without T cell depletion or irradiation can achieve a favourable outcome in Hurler's syndrome, with improved cognitive function, but with a limited effect on the corneas and skeleton.

Adolescent↗
PubMed2003

Learning the skills of flexible sigmoidoscopy - the wider perspective.

BACKGROUND: Nurse-led gastrointestinal endoscopy is a priority clinical area in the UK. Endoscopic procedures are challenging to learn, requiring a combination of technical competence (manipulating a flexible endoscope and interpreting the findings) and interpersonal skills (engaging effectively with a conscious patient who is frequently apprehensive). This paper explores the potential of an innovative, scenario-based approach which links a simulated patient with a computer-driven virtual reality (VR) training device for flexible sigmoidoscopy. Within this safe yet realistic quasi-clinical environment, learners carry out the procedure while interacting with the 'patient'. Communication skills are assessed by simulated patients, while quantitative performance data relating to the procedure is generated automatically by the VR simulator. METHODS: This pilot study took place within a nurse practitioner endoscopy course. A mixed methodology combined qualitative and quantitative data (observation and interview studies, communication rating scales and a range of computer-generated output measures from the VR simulator) in a multifaceted evaluation. RESULTS: Seven nurses took part in the study. Participants found the scenarios to be a convincing and powerful learning experience. All experienced high levels of anxiety. Simulated patients identified strengths in participants' communication skills, together with areas for development. Simulator-based practice led to an improvement in objective performance measures. DISCUSSION: Scenario-based training provides a powerful learning experience, allowing participants to build their technical expertise and apply it within a holistic clinical context without the risk of causing harm. We used this pilot study as a springboard for discussions over wider implications of procedure-based skills training, locating it within the literature on expertise and situated learning.

Clinical Competence↗
PubMed2003

Peritonitis due to the dermatiaceous mold Exophiala dermatitidis complicating continuous ambulatory peritoneal dialysis.

Exophiala (Wangiella) dermatitidis is a dermatiaceous mold that is an occasional cause of infection in the immunocompromised. We report a case of continuous ambulatory peritoneal dialysis-associated peritonitis probably due to environmental contamination with this organism. Prompt catheter removal and aggressive treatment with amphotericin B allowed an eventual return to peritoneal dialysis.

Exophiala↗
PubMed2003

Can early infection explain the sibling effect in adult atopy?

Atopy is strongly and inversely related to family size, a pattern which is plausibly assumed to reflect a protective effect of early infection. The current study tested this hypothesis by case-referent analysis of an adult cohort in the UK. The study established that atopy, defined by prick tests to common aeroallergens, was less common among those from larger families after adjustment for potentially confounding factors. In particular, a higher number of brothers appeared to offer protection. The current authors attempted to explain this distribution by examining contemporary family-doctor records of early childhood infections; and by a number of other indirect indices of early-life "hygiene". The sibling effect was unexplained by evidence of infection with either hepatitis A or Helicobacter pylori, or by counts of infections or antibiotic prescriptions in early life. There was a significant and independent negative association between the number of gastrointestinal infections before the age of 5 yrs and the odds of atopy. Dog ownership and home moving in early life also displayed potentially protective associations. Although the current study replicates the finding that atopy is inversely associated with family size this could not be explained by documentary or serological evidence of early infection. The findings support the suggestion that the "sibling effect" in atopy may not simply reflect protection by early infection.

Adult↗
PubMed2003

Determining clinician satisfaction with telemedicine.

We compared two methods of assessing clinician satisfaction with telemedicine. Clinicians completed a self-administered questionnaire with a preference ranking scale and a discrete choice method. Sixty-three clinicians completed the questionnaire (a 78% response rate). The preference ranking method showed that clinicians ranked the level of skill of the other clinician as the most important (55%) attribute of a teleconsultation and the completeness of the history as the second most important attribute (42%). The discrete choice method showed that clinicians ranked completeness of the patient's history as the most important attribute and risk of receiving wrong advice as the second most important. The use of discrete choice preferences provides an alternative and more objective method for collecting data about preferences in telemedicine. However, its use is not simple and requires the participants to be engaged in person rather than sent a questionnaire by post.

Adult↗
PubMed2003

Non-responders to hepatitis B vaccination: a review.

Hepatitis B virus (HBV) infection is a major public health issue throughout the world and vaccination of those at risk is the main method of containment. Of healthy vaccinees, 5-10% fail to mount an adequate antibody response. The antibody levels of an unknown further fraction of vaccinees fall considerably over time rendering them at a potential risk of infection. The scope of this article is to review the factors that might influence the immune response to HBV vaccination, to review the methods used to overcome the problem of poor response and to discuss what possible guidelines are available or needed in treating these vaccinees.

Hepatitis B↗
PubMed2003

Influence of bone invasion and extent of mandibular resection on local control of cancers of the oral cavity and oropharynx.

The aim of this paper was to evaluate the influence of bone invasion on treatment outcome among patients with cancers of the oral cavity and oropharynx and to determine whether or not outcome was influenced by the extent of mandibular resection. A review of 127 prospectively documented patients who were treated with marginal or segmental resection for oral (n = 110) and oropharyngeal (n = 17) cancers was undertaken. There were 97 males and 30 females with a median age of 61 years. Clinical T stages were: T1 17 patients, T2 33, T3 22, T4 55. Median followup was 4 years. A total of 94 patients underwent marginal resections and 33 underwent segmental resections. Histological bone invasion was present in 17 patients (16%) in the marginal resection group and 21 patients (64%) in the segmental group (P<0.05). Soft tissue surgical margins were positive in 11 patients (12%) in the marginal group and in seven patients (21%) in the segmental group (P=not significant). Local control did not correlate significantly with T stage, the extent of mandibular resection or the presence of histological bone invasion, but was significantly influenced by positive soft tissue margins (P<0.01). Among patients with bone invasion, the local control rate was higher following segmental resection when compared to marginal resections (87% vs 75%) but this was not statistically significant. Survival was significantly influenced by positive soft tissue margins but not bone invasion or the type of resection. We conclude that bone invasion alone did not predict for local control or survival rates among patients with oral and oropharyngeal cancers. Involved soft tissue margins were highly predictive of local recurrence and decreased survival. Conservative resection of the mandible is safe as long as marginal mandibulectomy does not lead to compromise of soft tissue margins. Segmental resection should be reserved for patients extensive bone invasion or those with limited invasion in a thin atrophic mandible.

Adult↗
PubMed2002

Intrauterine exposure to a maternal low protein diet reduces adult bone mass and alters growth plate morphology in rats.

Epidemiological studies suggest that poor growth during fetal life and infancy is associated with decreased bone mass in adulthood. However, theses observations have not, to date, been corroborated in animal models. To address this issue we evaluated the influence of maternal protein restriction on bone mass and growth plate morphology among the adult offspring, using a rat model. Maternal protein restriction resulted in a reduction in bone area and BMC, but not BMD, among the offspring in late adulthood. The widened epiphyseal growth plate in the protein-restricted offspring is compatible with the programming of cartilage and bone growth by maternal nutrition in early life.

Absorptiometry, Photon↗