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Biomedical subjects

S Dixon

Publications and source records attributed to S Dixon.

At least 55 records · Page 3Linked to original sources
PubMed1999

Estimating the benefits of community water fluoridation using the willingness-to-pay technique: results of a pilot study.

OBJECTIVES: To estimate the health and non-health effects of fluoridation on well-being using the willingness-to-pay technique. METHODS: A pilot study of 100 people was undertaken in which the willingness-to-pay technique was used to estimate the welfare effects of community water fluoridation in the city of Sheffield, in the United Kingdom. In view of the pilot nature of the study, it was decided to use quota sampling based on age and sex rather than random sampling. Reasons for respondents' answers and their previous knowledge of fluoridation were also noted. RESULTS: Sixty-two percent of respondents were in favour of fluoridation, 31% were opposed, and 7% were unsure. Thirty-one respondents refused to answer the willingness-to-pay questions. The mean willingness to pay for those in favour of fluoridation was less than that for those opposed to fluoridation. The main reasons given for opposing fluoridation were its impact on freedom of choice and the desire for pure water. Nineteen percent of the sample held incorrect information on the effects of fluoridation. CONCLUSIONS: The study illustrates how a simple referendum can miss important information regarding the intensity of individuals' preferences. An important aspect of the willingness-to-pay technique is its ability to identify 'losers' and quantify their welfare loss. This issue has been ignored by all previous economic evaluations of fluoridation. Further investigation is required to replicate this work on a larger sample of individuals, and to develop the willingness-to-pay technique.

Adolescent↗
PubMed1999

The effect of vaccines and antimicrobials on the formation of injection site lesions in subprimals of experimentally injected beef calves.

Two hundred and thirty-nine beef calves were used to determine the occurrence of injection site lesions at slaughter (16 to 17 mo of age) following the use of 3 different 8-way clostridial bacterins, a 4-way viral respiratory vaccine, various long-acting oxytetracycline preparations, florfenicol, ceftiofur, and trimethoprim-sulfa when injected in the top hip (top butt), thigh (round), or neck (blade) of calves at 2 to 3 or 5 to 7 mo of age. The occurrence of lesions varied by product, route of administration, and location of injection. The number of steaks affected with lesions, the trim weight of lesions, the histological class of lesions, and the economic losses from trim are described.

Animals↗
PubMed1998

Cost effectiveness of community leg ulcer clinics: randomised controlled trial.

OBJECTIVES: To establish the relative cost effectiveness of community leg ulcer clinics that use four layer compression bandaging versus usual care provided by district nurses. DESIGN: Randomised controlled trial with 1 year of follow up. SETTING: Eight community based research clinics in four trusts in Trent. SUBJECTS: 233 patients with venous leg ulcers allocated at random to intervention (120) or control (113) group. INTERVENTIONS: Weekly treatment with four layer bandaging in a leg ulcer clinic (clinic group) or usual care at home by the district nursing service (control group). MAIN OUTCOME MEASURES: Time to complete ulcer healing, patient health status, and recurrence of ulcers. Satisfaction with care, use of services, and personal costs were also monitored. RESULTS: The ulcers of patients in the clinic group tended to heal sooner than those in the control group over the whole 12 month follow up (log rank P=0.03). At 12 weeks, 34% of patients in the clinic group were healed compared with 24% in the control. The crude initial healing rate of ulcers in intervention compared with control patients was 1.45 (95% confidence interval 1.04 to 2. 03). No significant differences were found between the groups in health status. Mean total NHS costs were 878.06 pounds per year for the clinic group and 859.34 pounds for the control (P=0.89). CONCLUSIONS: Community based leg ulcer clinics with trained nurses using four layer bandaging is more effective than traditional home based treatment. This benefit is achieved at a small additional cost and could be delivered at reduced cost if certain service configurations were used.

Aged↗
PubMed1998

The contribution of lead-contaminated house dust and residential soil to children's blood lead levels. A pooled analysis of 12 epidemiologic studies.

In 1992, the U.S. Congress passed the Residential Lead-Based Paint Hazard Reduction Act, which requires the promulgation of health-based dust lead and soil lead standards for residential dwellings to prevent undue lead exposure in children. Unfortunately, the levels of lead in house dust and soil that are associated with elevated blood lead levels among U.S. children remain poorly defined. This pooled analysis was done to estimate the contributions of lead-contaminated house dust and soil to children's blood lead levels. The results of this pooled analysis, the most comprehensive existing epidemiologic analysis of childhood lead exposure, confirm that lead-contaminated house dust is the major source of lead exposure for children. These analyses further demonstrate that a strong relationship between interior dust lead loading and children's blood lead levels persists at dust lead levels considerably below the U.S. Department of Housing and Urban Development's current postabatement standards and the Environmental Protection Agency's guidance levels. Finally, these analyses demonstrate that a child's age, race, mouthing behaviors, and study-site specific factors influence the predicted blood lead level at a given level of exposure. These data can be used to estimate the potential health impact of alternative health-based lead standards for residential sources of lead exposure.

Child, Preschool↗
PubMed1998

Prevention and management of central venous catheter thrombosis.

Central venous catheters play an integral part in the treatment of patients with a variety of illnesses. Complications, although not common, do occur. However, the benefits of these devices far outweigh the risks. Thrombosis, one of the most common problems, can be divided into three distinct clinical entities. The prophylaxis, diagnosis, pathogenesis, and treatment of central venus catheter-related thromboses are critical in the treatment of patients requiring long-term venous access.

Catheterization, Central Venous↗
PubMed1998

PCP-A1, a defensin-like Brassica pollen coat protein that binds the S locus glycoprotein, is the product of gametophytic gene expression.

Self-incompatibility (SI) in Brassica species is controlled by a single polymorphic locus (S) with multiple specificities. Two stigmatically expressed genes that have been cloned from this region encode the S locus glycoprotein (SLG) and S receptor kinase (SRK). Both appear to be essential for the operation of SI. It is believed that rejection of incompatible pollen grains is effected by recognition events between an as yet unidentified S locus-encoded pollen coating-borne protein and the SLG/SRK. We previously identified a small pollen coat protein PCP7 (renamed here PCP-A1, for pollen coat protein, class A, 1) that binds with high affinity to SLGs irrespective of S genotype. Here, we report the cloning of PCP-A1 from Brassica oleracea and demonstrate that it is unlinked to the S locus. In situ localization of PCP-A1 transcripts revealed that they accumulate specifically in pollen at the late binucleate/trinucleate stage of development rather than in the tapetum, which previously was taken to be the principal source of the pollen coat. PCP-A1 is characterized by the presence of a structurally important motif consisting of eight cysteine residues shared by the plant defensins. Based on the presence of this motif and other data, homology modeling has been used to produce a putative structure for PCP-A1. Protein-protein interaction analyses demonstrate that SLG exists in monomeric and dimeric forms, both of which bind PCP-A1. Evidence is also presented for the existence of putative membrane-associated PCP-A1 binding proteins in stigmatic tissue.

Amino Acid Sequence↗
PubMed1998

The costs of early hearing screening in England and Wales.

A survey was carried out in 10 centres in England and Wales to determine the costs of hearing screening in the first year of life. The screens that were studied were targeted neonatal, universal neonatal, and the health visitor distraction test (HVDT) or alternative surveillance. Valid data were available from five centres for targeted neonatal screening (TNS), three for universal neonatal screening (UNS), and nine for the HVDT, although only five of the HVDT screens had valid data for follow up costs. The neonatal costs were consistent across the centres surveyed, whereas those for the HVDT screen varied considerably. The mean service costs for TNS, UNS, and the HVDT at 1994 prices were 5052 Pounds, 13,881 Pounds, and 24,519 Pounds for a standardised district of 1000 live births. Three conclusions seem justified. Firstly, UNS need not be prohibitively expensive as it costs considerably less than HVDT screening. Secondly, TNS appears to be a relatively inexpensive way of improving the age of identification of a proportion of the congenitally hearing impaired. Thirdly, given the published yields for UNS and the HVDT, the results indicate that UNS offers the most cost effective overall approach with alternative systems in place to identify late onset permanent hearing losses.

England↗
PubMed1998

Injection site survey in Canadian-fed cattle: spring 1997.

A 2nd injection site survey was conducted during the spring of 1997 in Canadian-fed beef. The prevalence of lesions was 13.3% in top butts, 23.1% in blades, 9.1% in eye of rounds, 7.5% in outside rounds, and 1.4% in inside rounds. Losses were $8.05/head processed or $17 million annually.

Animals↗
PubMed1997

Improving uptake of breast screening in multiethnic populations: a randomised controlled trial using practice reception staff to contact non-attenders.

OBJECTIVES: To determine whether a two hour training programme for general practice reception staff could improve uptake in patients who had failed to attend for breast screening, and whether women from different ethnic groups benefited equally. DESIGN: Controlled trial, randomised by general practice. SETTING: Inner London borough of Newham. SUBJECTS: 2064 women aged 50-64 years who had failed to attend for breast screening. Women came from 26 of 37 eligible practices, 31% were white, 17% were Indian, 10% Pakistani, 14% black, 6% Bangladeshi, 1% Chinese, 4% were from other ethnic groups, and in 16% the ethnic group was not reported. MAIN OUTCOME MEASURES: Attendance for breast screening in relation to ethnic group in women who had not taken up their original invitation. RESULTS: Attendance in the intervention group was significantly better than in the control group (9% v 4%). The response was best in Indian women--it was 19% in the intervention group and 5% in the control group. CONCLUSIONS: This simple, low cost intervention improved breast screening rates modestly. Improvement was greatest in Indian women--probably because many practice staff shared their cultural and linguistic background. This intervention could be effective as part of a multifaceted strategy to improve uptake in areas with low rates.

Asia↗
PubMed1997

The application of evidence-based priority setting in a District Health Authority.

BACKGROUND: Despite the current drive towards evidence-based medicine, it is not clear how commissioners actually use research findings in making decisions on priority setting. This study describes an attempt to directly introduce evidence on the effectiveness of interventions into the annual priority setting process of a District Health Authority (DHA). METHODS: Literature searches were undertaken on proposals for Health Authority funding. The identified literature was then critically appraised, and relevant information was used by members of the Department of Public Health to score the individual bids in terms of health gain. These scores were then fed into the priority setting process. RESULTS: A total of 144 proposals for funding were submitted. For 6.2 per cent of proposals there was strong evidence to support the intervention, for 21.2 per cent there was fair evidence in support, and for 38.1 per cent there was poor evidence. A search was not possible for 16.8 per cent of the proposals. There was a moderate correlation between the strength of evidence for the effectiveness of the proposal and initial scoring of the proposal for health gain (r = 0.41, p < 0.001). At the end of the priority setting process there was no correlation between strength of evidence and priority ranking (r = 0.01, p = 0.97). CONCLUSIONS: It is feasible, but difficult, to use information resources and critical assessment of research evidence as part of the priority setting process of a DHA. The research evidence did appear to influence the initial assessment of proposals. However, the strength of the research evidence was not associated with the priority choices made by the DHA in its purchasing plan.

Databases, Bibliographic↗
PubMed1997

A survey of injection site lesions in fed cattle in Canada.

During November 1996 to January 1997, a survey was conducted at 5 Canadian purveyors to measure the prevalence of injection site lesions in the top butt, boneless blade, outside round, inside round, and eye of the round. As trimmers were cutting these subprimals into steaks, technicians monitored each steak for grossly obvious scars. These scars were trimmed, weighed, and scored as either a "clear scar," "woody callus," or "cyst." All scars were subsequently examined histologically and classified as a "clear scar," "woody callus," "scar with nodules," "mineralized scar," or "cyst." Pieces were observed for broken needles while being processed and none were found. The estimated prevalence of injection site lesions was 18.8% (95% CI, 16.4% to 21.2%) in top butts, 22.2% (95% CI, 18.8% to 25.7%) in boneless blades, 4.9% (95% CI, 3.6% to 6.3%) in the eye of round, 1.8% (95% CI, 1.1% to 2.9%) in the inside round, and 7.6% (95% CI, 5.6% to 9.8%) in the outside round. Some top butts originated from American fed cattle; the estimated prevalence of lesions was 9.0% (95% CI, 5.9% to 12.9%) in American top butts and 22.3% (95% CI, 19.4% to 25.3%) in Canadian top butts. The median weight of the lesions varied among subprimals and ranged from 64 g to 117 g. Histologically, 13% of the scars were clear scars, 47% were woody calluses, 5% were mineralized scars, 34% were scars with nodules, 0.2% were cysts, and 0.9% were normal fat infiltrations. An economic analysis estimated an average loss of $8.95 per fed animal processed or $19 million dollars annually to the Canadian beef industry from injection scars.

Animals↗
PubMed1996

Determining factors for the outcome of peripheral blood progenitor cells harvests.

This is a pilot retrospective study to investigate the factors that may affect the collection of peripheral blood progenitor cells (PBPC). Sixty-nine PBPC harvests in 18 cancer patients (median age 39.5; 8 males and 10 females) were performed during marrow recovery after chemotherapy and hematopoietic growth factors. Median number of nucleated cells (MNC) collected were 13.3 (range 2.3-44.5) x 10(9) per session. Median CFU-GM was 362 colonies (range 63-1,720) per 500,000 MNC. Neither sex, body weight, diagnosis, nor the number of days into leukapheresis was significantly associated with MNC and CFU-GM. Older patients tend to have higher CFU-GM in the PBPC harvests (P = .0437). Higher WBC on the day of harvest is significantly associated with higher yield of MNC after leukapheresis (P < .0001). Patients without any evidence of disease have significantly higher yield of MNC than those having local/distant metastases with or without marrow involvement (P = .0302 and .0446). For patients with metastatic disease, those with bone marrow involvement tend to have higher CFU-GM than those without bone marrow involvement although the difference is not statistically significant (P = .0559). Those patients who have received only one, or three and more chemotherapy regimens have a higher yield of MNC than those who have only two previous chemotherapy regimens (P = .036 and .0324). The mechanism of PBPC mobilization is also discussed. In view of the limited patient number in this study, the results should be confirmed by larger studies.

Adolescent↗
PubMed1996

Three teams improving thrombolytic therapy.

BACKGROUND: The American Heart Association (AHA) standard for delivering thrombolytic therapy to chest pain patients is 30 to 60 minutes after patient presentation to the emergency department. Three acute care hospitals in an integrated health system in northern California shortened the time of administration of thrombolytic agents to appropriate patients presenting with chest pain in the emergency department. FINDING THE SOLUTIONS: Physician-led multidisciplinary teams developed algorithms to reduce variation and decrease the thrombolytic administration process to 30 minutes. Changes were made to prehospital and hospital thrombolytic policies and staff practices. REALIZING RESULTS: Each of the three acute care hospitals reduced their thrombolytic administration time by 48% to 59% to levels within the AHA standard. LEARNING FROM THE PROCESS: Internal benchmarking for clinical processes promotes a synergy between hospitals and medical staffs for the improvement of patient care. Multidisciplinary teams, which include community representatives, achieve a thorough understanding of a process, which in turn reduces variation in practice and improves quality.

Algorithms↗