Biomedical subjects
D Ryan
Publications and source records attributed to D Ryan.
Liquid chromatography with electrospray ionisation mass spectrometric detection of phenolic compounds from Olea europaea.
The results demonstrate the potential of electrospray ionisation mass spectrometry for the specific detection of phenolic species in olives. Phenolic compounds were detected with greater sensitivity in the negative ion mode, but results from positive and negative ion modes were complementary with the positive ion mode showing structurally significant fragments. This is demonstrated by the identification of oleuropein and isomers of verbascoside. The structure of the latter were confirmed by retention, mass spectral and nuclear magnetic resonance data. These isomers have not previously been reported in olive.
Combined sentinel lymph-node mapping and bone-marrow micrometastatic analysis for improved staging in breast cancer.
In a prospective study of 29 patients with clinically node-negative breast cancer, sampling of rib marrow was superior to sampling of iliac-crest marrow for detection of micrometastases. Combination of marrow micrometastatic analysis with sentinel lymph-node mapping may improve accuracy of staging in breast cancer.
Public health. Historical novel.
Public health thinking has failed to keep pace with changes in society. A basic shift is needed to address the needs of a deindustrialised society. Attention should be given to promoting self-esteem as a way of encouraging healthy living.
Non-PCR-dependent detection of the factor V Leiden mutation from genomic DNA using a homogeneous invader microtiter plate assay.
BACKGROUND: The goal of this study was to compare the Invader technology for the direct detection of the Factor V Leiden mutation from genomic DNA with a conventional polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. METHODS AND RESULTS: In the Invader assay, a specific upstream "invading" oligonucleotide and a partially overlapping downstream probe together form a specific structure when bound to complementary DNA template. This structure is recognized and cut at a specific site by the Cleavase enzyme, resulting in release of the 59 flap of the probe oligonucleotide. This fragment now serves as the "Invader" oligonucleotide with respect to synthetic secondary targets and secondary fluorescently labeled signal probes contained in the reaction mixture, resulting in specific cleavage of the secondary signal probe by the Cleavase enzyme. Fluorescence signal is generated when this secondary probe, labeled with dye molecules capable of fluorescence resonance energy transfer, is cleaved. Genomic DNAs isolated from peripheral blood buffy coats of patients previously tested for the Factor V Leiden mutation by PCR-RFLP were tested using an Invader assay specific for this mutation. In all 48 samples containing sufficient DNA for testing (30 normal, 16 heterozygous, 2 homozygous mutant), the genotype determined by the Invader assay was concordant with the PCR-RFLP results. CONCLUSION: These results indicate that a simple microtiter plate-based Invader assay can reliably genotype routine clinical patient samples for the Factor V Leiden point mutation without the need for PCR amplification, restriction enzyme digestion, or gel electrophoresis.
Nitric oxide synthetase and Helicobacter pylori in patients undergoing appendicectomy.
BACKGROUND: This study was designed to determine whether Helicobacter pylori forms part of the normal microenvironment of the appendix, whether it plays a role in the pathogenesis of acute appendicitis, and whether it is associated with increased expression of inducible nitric oxide synthetase (iNOS) in appendicular macrophages. METHODS: Serology for H. pylori was performed on 51 consecutive patients undergoing emergency appendicectomy. Appendix samples were tested for urease activity, cultured and stained for H. pylori, graded according to the degree of inflammatory infiltrate, and probed immunohistochemically for iNOS expression. RESULTS: The mean age of the patients was 21 (range 7-51) years. Seventeen patients (33 per cent) were seropositive for H. pylori but no evidence of H. pylori was found in any appendix specimen. However, an enhanced inflammatory cell infiltration was observed in seropositive patients (P < 0.04) and the expression of macrophage iNOS in the mucosa of normal and inflamed appendix specimens was increased (P < 0.01). CONCLUSION: H. pylori does not colonize the appendix and is unlikely to be a pathogenic stimulus for appendicitis. Priming effects on mucosal immunology downstream from the foregut may occur after infection with H. pylori.
Present and future management of asthma and COPD: proceedings from WONCA 1998.
On 15 June 1998, a workshop on asthma and chronic obstructive pulmonary disease (COPD) was held at the WONCA conference in Dublin. Based on the current guidelines for diagnosis and treatment of asthma and COPD, new developments and present and future research projects were discussed. Based on these guidelines and the research findings, new developments were positioned. The final conclusion of this workshop was that there is a need to continue exchanging ideas at an international level. So an initiative to start a Scientific Group of Primary Care Research within the European Respiratory Society has been taken.
Physical activity in the prevention and treatment of obesity and its comorbidities: evidence report of independent panel to assess the role of physical activity in the treatment of obesity and its comorbidities.
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Physical activity in the prevention and treatment of obesity and its comorbidities.
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Orbital Kimura's disease in a white child.
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Protecting children from lead poisoning and building healthy communities.
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Toward improving the reliability of clinical acupuncture trials: arguments against the validity of "sham acupuncture" as controls.
In refining the design of single-blind acupuncture research trials, "sham acupuncture" has been proposed and used in trials as a useful "inactive" control, yet the degree of inactivity with sham acupuncture points remains largely undetermined. With neural and dermal effects occurring whenever a needle is inserted into the skin, regardless of depth or location, the estimated effect upon Qi when needling sham acupuncture points remains a matter of conjecture. This paper examines the statistical consequences of utilizing sham acupuncture as a control when its energetic and biomedical effects are unknown. It argues the need for a more careful consideration of "assumptions" in clinical research design.
Optimal harvesting with both population and price dynamics.
We consider the effects of large inflationary price fluctuations on the computed optimal harvest strategy for a randomized Schaefer model. Both prices and population sizes are assumed random with both background (Wiener) and jump (Poisson) components. Population fluctuations are assumed to be density independent, i.e., relative changes are independent of population size. Stochastic dynamic programming is employed to find the optimal harvesting effort and economic return for a realistic set of bioeconomic data for Pacific halibut. It is found that inflationary effects have a pronounced influence on the optimal return, even in a hazardous or disastrous environment. However, optimal harvesting effort levels are much less sensitive to inflationary effects.
Fringe boundaries coincide with Notch-dependent patterning centres in mammals and alter Notch-dependent development in Drosophila.
In both vertebrate and invertebrate development, cells are often programmed to adopt fates distinct from their neighbors. Genetic analyses in Drosophila melanogaster have highlighted the importance of cell surface and secreted proteins in these cell fate decisions. Homologues of these proteins have been identified and shown to play similar roles in vertebrate development. Fringe, a novel signalling protein, has been shown to induce wing margin formation in Drosophila. Fringe shares significant sequence homology and predicted secondary structure similarity with bacterial glycosyltransferases. Thus fringe may control wing development by altering glycosylation of cell surface and/or secreted molecules. Recently, two fringe genes were isolated from Xenopus laevis. We report here the cloning and characterization of three murine fringe genes (lunatic fringe, manic fringe and radical fringe). We find in several tissues that fringe expression boundaries coincide with Notch-dependent patterning centres and with Notch-ligand expression boundaries. Ectopic expression of murine manic fringe or radical fringe in Drosophila results in phenotypes that resemble those seen in Notch mutants.
Strategies to maintain the credibility of sham acupuncture used as a control treatment in clinical trials.
Many clinical trials concerning acupuncture are flawed by methodological problems. One of the major difficulties is the appropriate selection and use of a placebo control. This article evaluates the use of sham acupuncture as a placebo control and analyzes its credibility as a control treatment. Sixty-four subjects were assessed for their perception of whether they were receiving sham or real acupuncture while participating in a clinical trial of acupuncture. It was found that if used under specific experimental conditions, sham acupuncture can function as a credible control. Specific strategies are suggested to maintain the credibility of sham acupuncture as a placebo control.
Effect of aggressive daunomycin therapy on survival in acute promyelocytic leukemia.
The Southwest Oncology Group analyzed outcome with cytotoxic chemotherapy for previously untreated acute myeloblastic leukemia (AML) from 1982 through 1986. Results with acute promyelocytic leukemia (APL) prompted comparison with patients from 1986 through 1991 and analysis of factors contributing to APL results. Patient and disease characteristics and treatment outcome were compared for all evaluable patients, with more detailed analysis of factors affecting APL treatment outcome. From 1982 through 1986, median survival and disease-free survival in 45 APL patients were 106 months and greater than 105 months, respectively, versus 6 and 14 months for 417 other AML patients. Such differences were not seen from 1986 through 1991. In the 141 APL patients from 1982 through 1991, after adjusting for significant patient and disease characteristics, higher daunomycin (DNR) doses during induction were significantly associated with higher complete remission rates (P < .0001), longer survival (P < .0001), and longer DFS (P < .0001). Cytosine arabinoside (Ara-C) induction dose, the inclusion of other chemotherapy agents in induction, postremission therapy (consolidation, maintenance, or bone marrow transplantation) other than DNR, APL subtype, and patient age did not appear to significantly affect outcome of APL, except for a significant detrimental effect of high-dose Ara-C in consolidation (P = .0042). Morphologic AML subtypes other than APL did not affect outcome. We conclude that high-dose DNR selectively increases survival in APL. This good survival is important for evaluation of combined all-trans retinoic acid (ATRA)/chemotherapy protocols and for planning future combinations of chemotherapy and ATRA. These results illustrate the need to individualize chemotherapy for subtypes of AML. Therapeutic response of APL is independent of age. Except for APL, morphologic subclassification of AML contributed little prognostic information.
Delayed omega-3 fatty acid supplements in renal transplantation. A double-blind, placebo-controlled study.
An earlier reported trial suggests that omega-3 fatty acids in fish oil supplements at 6 g/day with administration commencing at the time of engraftment may reduce acute CsA renal dysfunction. When started at the time of renal transplant, there are improvements in renal hemodynamics and blood pressure, and a decrease in rejection episodes. To examine the effect of later introduction of omega-3 fatty acids, 133 cadaver renal transplant recipients received CsA, prednisone, and AZA for 16 weeks (period 1). If patients were stable without rejection or infection activity, they were randomized to 9 g of eicosapentanoic acid (EPA), 18 g of EPA, 9 g of corn oil, or 18 g of corn oil in 1-g capsules as supplements. Glomerular filtration rate, renal blood flow, number of rejection episodes, blood pressure, and episodes of CsA nephrotoxicity were followed for 26 weeks in a double-blind manner (period 2). Ninety patients were evaluable and completed the protocol. There were 50 corn oil placebo patients, 22 low dose EPA patients, and 18 high dose EPA patients. In period 1, there were 27 rejection episodes in 21 patients without differences among subsequent treatment groups. In period 2, there were 13 rejection episodes in 4 patients. No patient with an EPA level in plasma statistically higher than placebo had a rejection episode. All allografts functioned for the entire 6 months with none lost to rejection. All 5 episodes of acute CsA nephrotoxicity occurred in placebo-treated patients without differences in whole blood CsA among toxic patients, other placebo patients, and EPA-treated recipients. At the end of the study, there were no differences in glomerular filtration rate, renal blood flow, or creatinine clearance among groups. Diastolic blood pressure fell by 9 mmHg during period 2 in high dose fish oil recipients and by 10 mmHg in low dose fish oil recipients (P < 0.05), while it rose by 2 mmHg in placebo patients. No serious adverse effects of EPA supplements were noted, although compliance based on plasma EPA was erratic. Based on our experience and that in the literature, administration of omega-3 fatty acids for purposes of kidney protection would seem to be most useful when started early after surgery. Late administration in our study was associated with minor clinical benefits.