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Biomedical subjects

B Delaney

Publications and source records attributed to B Delaney.

At least 37 records · Page 2Linked to original sources
PubMed2003

How evidence based are recruitment strategies to randomized controlled trials in primary care? Experience from seven studies.

BACKGROUND: Failure to recruit adequate numbers of participants represents a major barrier to the completion of randomized controlled trials in primary care and is associated with substantial opportunity costs. However, uncertainty exists regarding the relative effectiveness of different methods to promote recruitment. OBJECTIVES: The purpose of this study was to estimate the proportion of strategies used to promote patient recruitment to randomized controlled trials in primary care that are evidence based. METHODS: Investigators from seven primary care-based clinical trials of dyspepsia management aiming to recruit a total of 6070 patients participated. Following a survey of trial organization, a Delphi technique was used to reach consensus on levels of evidence on the effectiveness of interventions or organizational characteristics in influencing recruitment. The main outcome measures were the proportions of interventions or organizational characteristics for influencing patient recruitment that are based upon randomized controlled trials, on convincing non-experimental evidence or meeting neither of these criteria. RESULTS: Out of a total of 56 interventions used across the trials, 35 (63%) were judged as evidence based. Out of a total of 29 organizational characteristics possessed by the trials, five (17%) were judged as evidence based. Across the seven dyspepsia trials, the presence of 'favourable' organizational characteristics appeared to be important contributors towards successful recruitment. CONCLUSIONS: A wide range of interventions and organizational characteristics with the potential to promote recruitment were used or possessed by seven primary care trials. Many were not evidence based. Our experience suggests that organizational characteristics could be more influential in trial recruitment than the use of specific interventions. Given the costs of primary care-based trials, researchers need more rigorous evidence to inform recruitment strategies.

Dyspepsia↗
PubMed2002

Genetic toxicity of a standardized mixture of citrus polymethoxylated flavones.

Flavonoids are a ubiquitous family of phytochemicals that display a variety of biological effects, both beneficial and adverse depending on the individual compound. Certain flavonoids are genotoxic while others inhibit the genotoxicity of other mutagens. In the present studies, the mutagenicity of a mixture of polymethoxylated flavones (PMFs) purified from citrus peel oil was evaluated. The mixture consisted of nobiletin (32.5%), 3,3',4',5,6,7,8-heptamethoxyflavone (25.0%), tangeretin (14.0%), trimethylscutellarein (9.1%), sinensetin (3.9%), 5-demethyl-nobiletin (2.8%), hexa-O-methylquercetagetin (3.3%), 5-demethyl-tetramethylscutellarein (0.7%), 5-hydroxy-3,3',4',6,7,8-hexamethoxyflavone (0.7%), and a small quantity of unidentified flavonoid compounds (3.9%). In vitro addition of the PMF mixture over a concentration range that spanned four log doses (0.0005-5.0 mg/plate) did not reveal any evidence of mutagenicity in five bacterial tester strains (Salmonella typhimurium TA98, TA100, TA102, TA1535 and TA1537) either in the absence or presence of S9 activation. The PMF mixture exhibited a statistically significant increase in mutagenicity of L5178Y tk(+/-) mouse lymphoma cells at 0.05 (38.5 x 10(-6); P<0.05) and 0.1 mg/ml (61 x 10(-6); P<0.01) compared with vehicle-treated controls (mutation frequency=19.7 x 10(-6)). However, these responses were within historical values observed in negative control cultures and extremely small compared to the positive control (EMS 0.5 microl/ml; 1685.3 x 10(-6)). Furthermore, in the presence of S9 there was no indication of genetic toxicity in L5178Y tk(+/-) cells. These results demonstrate that the PMF mixture is not genotoxic in in vitro assay systems.

Animals↗
PubMed2001

Psychological interventions for non-ulcer dyspepsia.

BACKGROUND: Studies have also shown that NUD patients have higher scores of anxiety, depression, neurotism, chronic tension, hostility, hypochondriasis, and tendency to be more pessimistic when compared with the community controls. OBJECTIVES: This review aims to determine the effectiveness of psychological interventions including psychotherapy, psychodrama, cognitive behavioral therapy, relaxation therapy, guided imagery or hypnosis in the improvement of either individual or global dyspepsia symptom scores and also quality of life scores patients with non-ulcer dyspepsia (NUD). SEARCH STRATEGY: Trials were located through electronic searches of the Cochrane Controlled Trials Register (CCTR), MEDLINE, EMBASE, CINAHL and PsycLIT, using appropriate subject headings and text words and searching bibliographies of retrieved articles. SELECTION CRITERIA: All randomised controlled trials (RCTs) or quasi-randomised studies assessing the effectiveness of psychological interventions (including psychotherapy, psychodrama, cognitive behavioural therapy, relaxation therapy, guided imagery or hypnosis) for non-ulcer dyspepsia (NUD). DATA COLLECTION AND ANALYSIS: Data were collected on individual, global dyspepsia symptom scores, as well as measures of quality of life (QoL) scores and adverse effects. MAIN RESULTS: The three trials identified showed that there was improvement in the dyspepsia symptom scores at the end of treatment and one trial showed improvement in the psychological parameters. However, meta-analysis was not possible as these trials used different psychological interventions and two of the trials only reported mean change in symptoms and did not give standard deviations of this change. REVIEWER'S CONCLUSIONS: Psychological intervention in the form of psychodynamic psychotherapy and cognitive behavioral therapy may be useful in the treatment of NUD. However, we need more trials to assess dyspepsia symptom scores and also psychological intervention in order to give us a clearer picture of the role of psychological intervention in NUD.

Cognitive Behavioral Therapy↗
PubMed2001

Immunotoxicity of a standardized citrus polymethoxylated flavone extract.

Polymethoxylated flavones (PMFs) from citrus inhibit production of TNF-alpha and other pro-inflammatory cytokines. As TNF-alpha also modulates NK cell activity, the current studies were conducted to assess the potential for a standardized citrus PMF mixture to suppress humoral and innate immune functions. PMFs were isolated from orange peel oil using a procedure that obtained a consistent mixture of PMFs both in identity and proportion. The mixture consisted of nobiletin (30.7%), 3,3',4',5,6,7,8-heptamethoxyflavone (27.9%), trimethylscutellarein (14.5%), tangeretin (10.4%), sinensetin (5.8%), 5-demethyl-nobiletin (2.0%), hexa-O-methylquercetagetin (1.3%), 5-demethyl-tetramethylscutellarein (0.6%), and other flavonoids (2.7%). To assess the effect of the PMF mixture on humoral immune responses, female B(6)C(3)F(1) mice (n=8) were exposed to the PMF by gavage at 5, 50, 150 and 500 mg/kg/day for 28 days. On day 25, mice were sensitized to sRBC by tail vein injection and AFC response determined 4 days later. Humoral immunity was insensitive to suppression following exposure to all concentrations of the PMF mixture. Suppression of NK cell activity was observed only following 500 mg/kg/day for 28 days. Body weights were not affected by exposure to any concentration of the PMF mixture in sRBC immunized or non-immunized mice. However, in sRBC-immunized mice, higher concentrations of PMF were associated with a statistically insignificant increase in spleen weight (P>0.05). No change in spleen weight was observed in non-immunized mice. As anticipated, based on previously published in vitro observations, long-term, high-dose exposure to a standardized mixture of citrus PMFs caused a mild suppression of NK cell activity; however, humoral immunity was not sensitive to suppression at the same exposure levels.

Animals↗
PubMed2000

Systematic review and economic evaluation of Helicobacter pylori eradication treatment for non-ulcer dyspepsia. Dyspepsia Review Group.

OBJECTIVES: To evaluate efficacy and cost effectiveness of Helicobacter pylori eradication treatment in patients with non-ulcer dyspepsia infected with H pylori. DESIGN: Systematic review of randomised controlled trials comparing H pylori eradication with placebo or another drug treatment. Results were incorporated into a Markov model comparing health service costs and benefits of H pylori eradication with antacid treatment over one year. DATA SOURCES: Six electronic databases were searched for randomised controlled trials from January 1966 to May 2000. Experts in the field, pharmaceutical companies, and journals were contacted for information on any unpublished trials. Trial reports were reviewed according to predefined eligibility and quality criteria. MAIN OUTCOME MEASURES: Relative risk reduction for remaining dyspeptic symptoms (the same or worse) at 3-12 months. Cost per dyspepsia-free month estimated from Markov model based on estimated relative risk reduction. RESULTS: Twelve trials were included in the systematic review, nine of which evaluated dyspepsia at 3-12 months in 2541 patients. H pylori eradication treatment was significantly superior to placebo in treating non-ulcer dyspepsia (relative risk reduction 9% (95% confidence interval 4% to 14%)), one case of dyspepsia being cured for every 15 people treated. H pylori eradication cost pound56 per dyspepsia-free month during first year after treatment. CONCLUSION: H pylori eradication may be cost effective treatment for non-ulcer dyspepsia in infected patients but further evidence is needed on decision makers' willingness to pay for relief of dyspepsia.

Antacids↗
PubMed2000

Pharmacological interventions for non-ulcer dyspepsia.

BACKGROUND: The commonest cause of upper gastrointestinal symptoms is non-ulcer dyspepsia (NUD) and yet the pathophysiology of this condition has been poorly characterised and the optimum treatment is uncertain. It is estimated that pound450 million is spent on dyspepsia drugs in the UK each year. OBJECTIVES: This review aims to determine the effectiveness of six classes of drugs (antacids, histamine H2 antagonists, proton pump inhibitors, prokinetics, mucosal protecting agents and antimuscarinics) in the improvement of either the individual or global dyspepsia symptom scores and also quality of life scores patients with non-ulcer dyspepsia. SEARCH STRATEGY: Trials were located through electronic searches of the Cochrane Controlled Trials Register (CCTR), MEDLINE, EMBASE, CINAHL and SIGLE, using appropriate subject headings and text words, searching bibliographies of retrieved articles, and through contacts with experts in the fields of dyspepsia and pharmaceutical companies. SELECTION CRITERIA: All randomised controlled trials (RCTs) comparing drugs of any of the six groups with each other or with placebo for non-ulcer dyspepsia (NUD). DATA COLLECTION AND ANALYSIS: Data were collected on dyspeptic symptom scores either individual or global symptom assessments and also quality of life scores and adverse effects. MAIN RESULTS: A total of 11775 citations were obtained. 144 trials were retrieved and 94 trials fulfilled our eligibility criteria. However, subsequent data extraction was not possible in 37 trials. Fifty trials were excluded as they did not meet our eligibility criteria. The final 57 trials were included in the final meta-analysis. Prokinetics (12 trials with dichotomous outcomes generating 829 patients; relative risk reduction [RRR] = 50%; 95% confidence intervals [CI] = 30 to 65%) and H2RAs (8 trials generating 1,125 patients; RRR = 30%; 95% CI = 4 to 48%) were significantly more effective than placebo. Proton pump inhibitors (4 trials generating 1,248 patients; RRR = 12%; 95% CI = -1 to 24%) and Bismuth salts (6 trials generating 311 patients; RRR = 40%; 95% CI = -3 to 65%) were superior to placebo but this was of marginal statistical significance. Antacids (one trial generating 109 patients; RRR = -2%; 95% CI = -36% to 24%) and sucralfate (two trials generating 246 patients; RRR = 29%; 95% CI = -40% to 64%) were not statistically significantly superior to placebo. A funnel plot suggested that the prokinetic result could be due to publication bias. The funnel plot of H2RAs did not show any evidence of publication bias but the quality of the trials was generally poor. REVIEWER'S CONCLUSIONS: There is some evidence that anti-secretory therapy may be effective in NUD. The trials evaluating prokinetic therapy are difficult to interpret as the meta-analysis result could have been due to publication bias. Further research using prokinetics and anti-secretory therapy is required before any firm conclusions can be reached. The effect of these drugs is likely to be small and many patients will need to take them on a long-term basis so the therapies assessed need to be inexpensive and well tolerated.

Dyspepsia↗
PubMed2000

Eradication of helicobacter pylori for non-ulcer dyspepsia.

BACKGROUND: Helicobacter pylori (H pylori) is the main cause of peptic ulcer disease. The role of H pylori in non-ulcer dyspepsia is less clear. OBJECTIVES: To determine the effect of H pylori eradication on dyspepsia symptoms and quality of life scores in patients with non-ulcer dyspepsia. SEARCH STRATEGY: Trials were identified through electronic searches of the Cochrane Controlled Trials Register (CCTR), MEDLINE, EMBASE, CINAHL and SIGLE, using appropriate subject headings and keywords, searching bibliographies of retrieved articles, and through contacts with experts in the fields of dyspepsia and with pharmaceutical companies. SELECTION CRITERIA: All parallel group randomised controlled trials (RCTs) comparing drugs to eradicate H pylori with placebo or other drugs known not to eradicate H pylori for patients with non-ulcer dyspepsia. DATA COLLECTION AND ANALYSIS: Data were collected on individual and global dyspeptic symptom scores, quality of life measures and adverse effects. Dyspepsia outcomes were dichotomised into minimal/resolved versus same/worse symptoms. MAIN RESULTS: Seven randomised controlled trials were included in the systematic review. Five trials compared proton pump inhibitor dual or triple therapy with a proton pump inhibitor + placebo antibiotics, and evaluated dyspepsia at 6-12 months in 1,385 patients. H pylori eradication was significantly superior to placebo in treating non ulcer dyspepsia (relative risk reduction = 7%; 95% CI = 1% to 12%; p=0.02) and there was no significant heterogeneity between the studies. The number needed to treat to cure one case of dyspepsia = 19 (95% CI = 11 to 132). A further two trials compared Bismuth based H pylori eradication with an alternative pharmacological agent. These trials were smaller and had a shorter follow-up but suggested H pylori eradication was more effective than either H2 receptor antagonists or sucralfate in treating non-ulcer dyspepsia. REVIEWER'S CONCLUSIONS: H pylori eradication may be an effective therapy for H pylori positive non-ulcer dyspepsia. This result is not robust and further evidence on the efficacy of H pylori eradication in non ulcer dyspepsia would be helpful. The effect is modest and economic models would help establish whether this approach is cost-effective. This review will be updated as results from other ongoing trials (Malfertheiner 2000) are made available.

Anti-Bacterial Agents↗
PubMed2000

Near-patient tests in primary care: setting the standards for evaluation.

Near-patient tests (NPT) are an area of rapid technological advance that may enhance the quality of care given by primary care physicians by enabling more accurate diagnosis or more reliable monitoring of therapy. Unfortunately, many new diagnostic technologies prove disappointing in practice, either because of limitations of the technology or because of a failure to address setting-specific issues that were not apparent during their evaluation. A recent systematic review of NPT in primary care has highlighted the methodological weaknesses of most published evaluations. There is a need for a formal statement of the criteria by which to judge the quality of evaluations in this field. In a similar fashion to Wilson and Junger's criteria for screening, seven questions need to be addressed. These cover the performance, reliability and acceptability of the test, its impact on decision-making, comparison with existing practice, cost-effectiveness of the test and integration with the practitioner's knowledge base. Evaluations of NPTs should therefore address the following methodological issues: demonstration of the need for the NPT, definition of the appropriate reference standard, calculation of sample size based on modelling of the decision problem and defining acceptable limits to the likelihood ratio, avoidance of verification bias, selection bias and treatment paradox, testing for the presence of spectrum bias, reporting the sensitivity of the results to changes in setting or prevalence or disease and calculating cost-effectiveness.

Humans↗
PubMed1998

Incidence and occupational pattern of leukaemias, lymphomas, and testicular tumours in western Ireland over an 11 year period.

STUDY OBJECTIVE: To determine incidence of the following malignancies, testicular tumours, all leukaemias and all lymphomas in the West of Ireland in an 11 year period. Secondly, to examine the relation between disease patterns and available occupational data in male subjects of working age. DESIGN: A census survey of all cases occurring in the three counties in the Western Health Board (WHB) area, Galway, Mayo and Roscommon, for the 11 year period 1980 to 1990 inclusive. Average annual age standardised incidence rates for the period were calculated using the 1986 census data. Rates for the area are compared with rates from the southern region of Ireland, which had a tumour registry. Trends over the time period are evaluated. All male subjects for whom occupational data were available were categorised using the Irish socioeconomic group classification and incidence rates by occupation were compared using the standardised incidence ratio method. In one of the counties, Galway, a detailed occupational history of selected cases and an age matched control group was also elicited through patients' general practitioners. SETTING: All available case records in the West of Ireland. RESULTS: There are no national incidence records for the period. Compared with data from the Southern Tumour Registry, the number of cases of women with myeloid leukaemias was significantly lower. Male leukaemia rates were significantly lower as a group (SIR 84 (95% CI 74, 95) but not when considered as individual categories. Regression analysis revealed an increasing trend in the number of new cases of non-Hodgkin's lymphoma among both men (r = 0.47, p = 0.02) and women (r = 0.90, p = 0.0001) and of chronic lymphocytic leukaemia in men (r = 0.77, p = 0.005) and women (r = 0.68 p = 0.02) in the WHB region over the last decade. Four hundred and fifty six male cases over the age of 15 years were identified and adequate occupational information was available for 74% of these. Standardised incidence ratios of testicular tumours 100, 938) and agriworkers other than farmers (SIR 377, 95% CI 103, 967). There were also significantly increased incidence ratios for both non-Hodgkin's lymphoma (SIR 169, 95% CI 124, 266) and three categories of leukaemias among farmers. Hodgkin's disease and acute myeloid leukaemias were significantly increased among semi-skilled people. Interview data with 90 cases and 54 controls of both sexes revealed that among farmers, cases (n = 31) were significantly less likely than controls (n = 20) to use tractor mounted spraying techniques (OR = 0.19 (95% CI 0.04, 0.80)) and less likely to wear protective masks (OR 0.22 (95% CI 0.05, 0.84)). CONCLUSIONS: Trends of increase in non-Hodgkin's lymphoma and some leukaemias are consistent with studies elsewhere. The study provides further evidence of the relation between agricultural work and certain lymphoproliferative cancers. The possible carcinogenic role of chemicals used in agricultural industries must be considered as an explanation.

Adolescent↗
PubMed1994

Induction of serum borne immunomodulatory factors in B6C3F1 mice by carbon tetrachloride. Exposure to carbon tetrachloride produces an increase in B-cell number and function.

Carbon tetrachloride exposure in mice induces a serum associated immunosuppressive factor(s) that inhibits T-cell dependent immune responses. The objective of the present studies was to characterize the immunomodulatory activity of serum isolated from carbon tetrachloride-treated mice on T-cell independent humoral immune responses. Direct addition of serum isolated from carbon tetrachloride-treated mice (500 mg/kg/day for 7 days) to naive spleen cell cultures enhanced the antibody forming cell response to lipopolysaccharide as compared to serum from naive or vehicle-treated mice. Enhanced antibody forming cell responses were also observed when spleen cells isolated from carbon tetrachloride-treated mice were sensitized with this T-cell independent antigen 24 h, but not 48 h or 72 h, following exposure of mice to one dose of 500 or 1000 mg/kg of carbon tetrachloride. Additionally, spleen weight and spleen:body weight ratio were increased in mice sensitized in vivo with sheep red blood cells 24 h after exposure to a single dose of carbon tetrachloride (500 or 1000 mg/kg) as compared to naive antigen sensitized mice and mice sensitized 48 and 72 h after exposure to carbon tetrachloride. Fluorescence activated cell sorting analysis indicated that daily exposure to carbon tetrachloride (250 or 500 mg/kg for 7 days) increased the percentage of B-cells in the spleen without altering the number of TH-cell or TC/S cell populations. Taken together, these results suggest that exposure to carbon tetrachloride induces a serum borne factor(s) that produces a modest increase in the functional activity and number of B-cells in the spleen.

Adjuvants, Immunologic↗
PubMed1994

Carbon tetrachloride suppresses T-cell-dependent immune responses by induction of transforming growth factor-beta 1.

In vivo exposure of B6C3F1 mice to the hepatotoxic chlorinated hydrocarbon, CCl4, suppresses T-cell-dependent humoral immune responses to sRBC. In the present studies, separation-crossover-reconstitution experiments with spleen cell subpopulations isolated from vehicle and CCl4-treated mice (500 mg/kg/day for 7 days) indicate that T-cells are the primary immunologic cell-type altered following CCl4 exposure. Despite suppression of T-cell activity, Con A-activated spleen cell supernatants from CCl4-treated mice produced greater amounts of biologically active IL-2 than untreated spleen cells. Furthermore, Con A-induced upregulation of the p55 subunit of the IL-2 receptor was not altered in spleen cells from CCl4-treated mice. The mediator of immune suppression is a serum-borne factor induced 48 hr following a single exposure to CCl4. Sera isolated from mice treated with CCl4 for 7 days (500 mg/kg/day) or 48 hr following a single exposure (1000 mg/kg) were found to possess high concentrations of TGF-beta 1. Direct addition studies demonstrated that T-cell-dependent AFC responses are more sensitive to suppression by TGF-beta 1 than are T-cell-independent responses. Finally, incubation of sera from CCl4-treated mice with TGF-beta 1-neutralizing mAb reversed the immune suppression associated with this serum. These results demonstrate that CCl4-induced immune suppression is at least partially mediated by induction of TGF-beta 1.

Animals↗