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D Wright

Publications and source records attributed to D Wright.

At least 73 records · Page 4Linked to original sources
PubMed2000

Algorithms for the computer modelling of mechanical interactions with soft tissue.

The computer modelling of soft tissue has applications in the simulation of surgical procedures, product design, and in CAD generally as well as in motion pictures. We begin by reviewing computer modelling techniques in a range of applications. Algorithms are described to predict where surfaces interact mechanically, aiming as far as possible to use geometric modelling methods available within high level CAD systems. After an initial 2-Dimensional evaluation, 3-dimensional surfaces were used throughout. A model was developed to predict the region of impact of two surfaces in an environment of many surface patches. We report the results of this modelling and the application of refinement algorithms to reduce the computation requirements. We then go on to discuss the applicability of this work in the modelling of the deformation behaviour of soft tissues.

Algorithms↗
PubMed2000

Communication and information needs of a random sample of community psychiatric nurses in the United Kingdom.

This paper reports on a cross-sectional survey investigating communication and information needs of community psychiatric nurses attached to community mental health teams in the United Kingdom. Community psychiatric nurses' access to and communication with other professionals was also assessed. In total, 200 teams were randomly sampled UK-wide, and postal questionnaires were sent to community psychiatric nurses attached to these teams; 110 questionnaires were completed and returned (55% response rate). Spearman's rho, Pearson's correlation and the chi-square test were used in bivariate analyses and multiple logistic regression in multivariate analysis. Participants reported to be mainly in contact with psychiatrists (71%) and other community psychiatric nurses (52%). Eighty-four per cent and 91% reported psychiatrists and community psychiatric nurses, respectively, to be quite/extremely helpful when consulted; the proportions were lower for general practitioners and counsellors/therapists (32% and 31%, respectively). All reported lack of time and 84% reported communication problems with other professionals as barriers to their work. Although 70% reported having the necessary training/skills for managing severe cases, 76% indicated they had information needs. Being a long-serving community psychiatric nurse (OR = 4.51, 95% CI = 1.06-19.20), perceiving the discussion of cases with other professionals as less helpful (OR = 4.82, 95% CI = 1.16-20.01), being mainly in contact with other CPNs (OR= 6.72, 95% CI= 1.21-37.15), reporting not having the necessary training/skills (OR = 7.78, 95% CI = 1.37-44.25), and wanting information on mental health law (OR= 12.27, 95% CI = 1.75-86.36) were significant predictors of having information needs. This survey provided valuable information on problems facing these nurses and highlighted the need for training and for easier access to and increased communication with other professionals.

Adult↗
PubMed1999

Comparison of long-term outcomes of atrial repair of simple transposition with implications for a late arterial switch strategy.

BACKGROUND: We report the single-institution, long-term results of 358 patients with simple transposition of the great arteries surviving >30 days after a Mustard (n=226, 1965 to 1980) or Senning (n=132, 1978 to 1992) procedure. METHODS AND RESULTS: Outcome measures included late death, reintervention, ECG and ambulatory ECG rhythm, new arrhythmia, and functional status. Average follow-up was 13.4 (range 0.32 to 17.9) years for the Senning group and 11.7 (range 0.04 to 23.9) years for the Mustard group. The Senning group had a better survival rate at 5, 10, and 15 years (95% versus 86%, 94% versus 82%, and 94% versus 77%, respectively). In both groups, the majority of late deaths were sudden, without preceding ventricular dysfunction. Survival and survival free of reintervention were significantly better in the Senning group (relative risk [RR] 0.34, P=0.06 versus RR 0.39, P=0.027). Loss of sinus rhythm was comparable and unrelated to death. After era correction, the incidence of atrial flutter was similar and strongly associated with late death in both groups. Clinical systemic ventricular failure was uncommon, and at last follow-up, 92% of the Senning group and 89% of the Mustard group were in New York Heart Association class I. In a model exploring the implications of elective arterial switch conversion, this would only be beneficial if the hazard late after switch was markedly reduced and/or the hazard after the Senning procedure increased with time. CONCLUSIONS: Late outcomes after the Senning procedure are superior to those after the Mustard procedure. Both groups had late sudden deaths that were not associated with clinical systemic ventricular failure. Good functional status after the Senning procedure suggests that a strategy of elective switch conversion cannot be justified for patients with isolated transposition.

Cardiac Surgical Procedures↗
PubMed1999

Clinical value of mammography for symptomatic women 35 years of age and younger.

OBJECTIVE: This retrospective observational study was designed to answer the following question: Is mammography clinically effective in the evaluation of women </=35 years old with breast symptoms or findings. STUDY DESIGN: A retrospective review was undertaken of 1908 consecutive initial mammogram reports of symptomatic women </=35 years old who came to a referral breast clinic. The clinic records were analyzed for the working diagnoses and management plans before and after the input of the initial mammogram reports. RESULTS: Of the 4160 initial mammograms of women who came (1992-1995) to the Breast Diagnostic Center at Women's and Children Hospital, Los Angeles, Calif, 1908 were of women </=35 years old. The mammogram reports were reviewed and tabulated by age group for mammography recommendations. The working diagnoses and management plans in the center's charts were retrospectively evaluated before and after the mammogram reports to ascertain whether the mammogram reports altered clinical management in this patient population and age group. No clinically unsuspected cancers were perceived by mammography performed at the center in women </=35 years old. (All of the 23 invasive cancers were palpable and had prior diagnoses after fine-needle aspiration biopsy.) The initial mammogram reports did not change the working diagnosis or clinical management of these cases in this patient population and clinic setting. Ultrasonography was recommended by the radiologists in 37% of the study cases. CONCLUSIONS: Routine initial mammography was not cost-effective or clinically beneficial in the evaluation of breast symptoms or findings and management of the cases of women </=35 years old who came to our center.

Adenocarcinoma↗
PubMed1999

Gestational diabetes mellitus: metabolic and blood glucose parameters in singleton versus twin pregnancies.

OBJECTIVES: This study compared the frequency, glucose tolerance test results, and parameters of blood glucose control in twin and singleton pregnancies associated with gestational diabetes mellitus and carbohydrate intolerance. STUDY DESIGN: Twin and singleton pregnancies associated with gestational diabetes mellitus and carbohydrate intolerance were compared as follows: frequency, maternal age, weight, 1-hour screen, glucose tolerance test results, posttreatment blood glucose values, insulin requirement, and insulin dose. Statistical analysis included the chi(2) and Student t tests. RESULTS: Gestational diabetes mellitus was increased in twins (7.7% vs 4.1%; P <.05). The maternal weight at first visit was significantly less, and the 3-hour glucose tolerance test value was significantly greater than that for singletons. The other parameters were not different. CONCLUSIONS: There is a significant increase in the incidence of gestational diabetes mellitus and disturbance of the 3-hour glucose tolerance test in twin pregnancies. However, insulin requirements were not different, suggesting a mild disturbance of carbohydrate tolerance that was effectively managed by the strategies used to achieve blood glucose control in singletons.

Blood Glucose↗
PubMed1999

Nevoid keratosis of the nipple.

A patient with nevoid keratosis of the nipple is described. The clinical features, histology, therapy, and prognosis are discussed.

Adult↗
PubMed1999

Early house moves, indoor air, heating methods and asthma.

OBJECTIVES: To assess whether house moves or certain housing conditions are a risk factor for the development of childhood asthma. DESIGN: A case-control study of asthmatic and non-atopic children aged 4-16 years. SUBJECTS: One hundred children with confirmed asthma in a group general practice of 11000 patients in Plymouth, U.K. Each was matched by age and gender with a child with no history of wheeze, eczema or hay fever. MAIN OUTCOME MEASURES: House moves and main heating methods, prior to the age of onset of asthma in cases and controls. RESULTS: There was a non-significant association between early house moves and the subsequent development of asthma. No association was found with heating methods, except for ducted-air heating which, because of the small numbers involved could have occurred by chance. None of the other factors studied affecting indoor air showed an association. CONCLUSION: Moving house at an early age may increase the risk of developing asthma, or may be associated with other more important risk factors, such as increased general mobility and hence, exposure to viral infections. Heating methods or other factors likely to affect the indoor air quality in early life were not useful predictors of subsequent asthma in children.

Adolescent↗
PubMed1999

Redox imbalance differentially inhibits lipopolysaccharide-induced macrophage activation in the mouse liver.

Endotoxemia is accompanied by significant changes in the reductive-oxidative (redox) balance of critical target organs. Redox stress has been shown to regulate the expression of proinflammatory genes that are induced by endotoxic lipopolysaccharide (LPS) in vitro; however, much less is known about the effects of redox imbalance on LPS-induced gene expression in vivo. To assess the effects of redox stress on inflammatory responses in endotoxemia, mice were treated with either diethyl maleate (DEM), a glutathione-depleting agent, or buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis, and challenged with LPS. While serum tumor necrosis alpha (TNF-alpha) responses and the appearance of TNF-alpha-positive Kupffer cells in the liver were virtually eliminated by DEM or BSO treatment, the expression of both CD14 and inducible NO synthase (iNOS) by Kupffer cells was unaffected by glutathione depletion. By contrast, LPS-induced hepatocyte and hepatic sinusoidal endothelial cell iNOS expression was significantly inhibited in DEM-treated mice. Hepatocyte iNOS induced by recombinant mouse TNF-alpha was also inhibited by DEM treatment. These results indicate that the effects of oxidative stress in this organ are cell type specific and suggest that both the production and the action of TNF-alpha are substantially influenced by the redox state of the liver during endotoxemia.

Animals↗
PubMed1999

Assessment of the feasibility of conducting population prevalence studies of chronic renal failure according to ethnic group: a survey of clinical biochemistry laboratories in Greater London and south east England.

The planning of renal replacement therapy is based on assessment of population need for the white population, but uses historical trends in treatment uptake for black and Asian ethnic minority groups, for whom the incidence of chronic renal failure (CRF) is not known. Epidemiological studies of CRF are based upon follow-up of plasma creatinine results obtained from clinical biochemistry laboratories. We conducted a postal questionnaire survey of UK National Health Service (NHS) and private clinical biochemistry laboratories in Greater London and the south east of England to arrange the design and test the feasibility of carrying out a study to determine ethnic-specific rates of CRF. Fifty-five NHS laboratories (90%) and 19 private laboratories (57%) responded. Few pathology computer systems recorded ethnic group, patient post code, or diagnosis; although 31 of the laboratory computers (42%) were linked with the hospital Patient Administration System which could supply these data. Approximately 5.5 million electrolyte profiles and 20 million individual renal function tests are carried out annually in south east England. Ninety per cent of those were performed within NHS laboratories, implying that a study can use NHS sources alone without risk of any undue bias. Sixty laboratories (81%) included creatinine in their routine electrolyte profile, which would be a requirement for any study. Thirty-one laboratories (42%) archived tests within 1 year of entry, which would rule out a retrospective study design. A prospective study is feasible and should be carried out as soon as is practicable.

Clinical Laboratory Information Systems↗
PubMed1999

The sustainability of telemedicine projects.

Although there are instances where the provision of health care is successfully driven by the profit motive, in most countries it is considered a public service. The provision of telemedicine services assuredly meets an important social need to extend health care to remote and rural areas in developing countries. While there are potential advantages and benefits from telemedicine, the evidence of its cost-effectiveness and sustainability is meagre. Telemedicine undoubtedly yields cost savings in certain circumstances, but few service providers have found a way to recover their costs (and make a profit) from those to whom they provide their service. With their low expenditures per person, developing countries face a daunting challenge in making such public services sustainable. Pilot projects should be a first step in demonstrating the cost-effectiveness and benefits of telemedicine, but such projects should also be sustainable. Sponsors of such pilot projects must have a clear plan from the start about how the project can continue after the sponsorship comes to an end. This paper examines ways in which telemedicine services can be made sustainable.

Capital Financing↗
PubMed1999

Tension-free mesh hernia repair: recovery and recurrence after one year.

The outcome of 200 consecutive patients with inguinal hernias repaired by the tension-free mesh technique at a specialist clinic was assessed one year after operation. There were no recurrences and no major complications. The wound infection rate was 1%. Less than 10% of patients had only minor complaints and 99% of patients were satisfied or very satisfied with the operation and its outcome. Low recurrence rates after one year imply low long-term recurrence and testify to the benefits of a specialist approach.

Adolescent↗