PubMed Health⌕ Search

Biomedical subjects

David Bruce

Publications and source records attributed to David Bruce.

11 recordsLinked to original sources
PubMed2006

Complete genome sequence of Haemophilus somnus (Histophilus somni) strain 129Pt and comparison to Haemophilus ducreyi 35000HP and Haemophilus influenzae Rd.

Haemophilus somnus can be either a commensal of bovine mucosal surfaces or an opportunistic pathogen. Pathogenic strains of H. somnus are a significant cause of systemic disease in cattle. We report the genome sequence of H. somnus 129Pt, a nonpathogenic commensal preputial isolate, and the results of a genome-wide comparative analysis of H. somnus 129Pt, Haemophilus influenzae Rd, and Haemophilus ducreyi 35000HP. We found unique genes in H. somnus 129Pt involved in lipooligosaccharide biosynthesis, carbohydrate uptake and metabolism, cation transport, amino acid metabolism, ubiquinone and menaquinone biosynthesis, cell surface adhesion, biosynthesis of cofactors, energy metabolism, and electron transport. There were also many genes in common among the three organisms. Our comparative analyses of H. somnus 129Pt, H. influenzae Rd, and H. ducreyi 35000HP revealed similarities and differences in the numbers and compositions of genes involved in metabolism, host colonization, and persistence. These results lay a foundation for research on the host specificities and niche preferences of these organisms. Future comparisons between H. somnus 129Pt and virulent strains will aid in the development of protective strategies and vaccines to protect cattle against H. somnus disease.

Amino Acids↗
PubMed2006

Validating the Readiness for Interprofessional Learning Scale (RIPLS) in the postgraduate context: are health care professionals ready for IPL?

AIMS: This paper describes the process of validating the Readiness for Interprofessional Learning Scale (RIPLS) for use with postgraduate health care professionals. CONTEXT: The RIPLS questionnaire has proved useful in the undergraduate context, enabling tutors to assess the readiness of students to engage in interprofessional learning (IPL). With the drive in the National Health Service (NHS) to deliver health care in interprofessional teams, it seems logical to ask whether postgraduate education should, or could, be delivered successfully in interprofessional contexts. As a preliminary to undertaking an extended IPL project, the researchers tested the validity of the RIPLS tool in the postgraduate health care context. METHOD: A modified version of the RIPLS questionnaire was administered to all general practitioners, nurses, pharmacists and allied health professionals in the Dundee Local Health Care Cooperative (LHCC) (n = 799). A total of 546 staff responded (68%). RESULTS: Three factors, comprising 23 statements, emerged from the statistical analysis of the survey data, namely, teamwork and collaboration, sense of professional identity and patient-centredness. The internal consistency measure was 0.76. Analysis of variance suggested some key differences between the different professions in respect of the factors. CONCLUSIONS: The RIPLS questionnaire was validated for use in the postgraduate context, thus providing researchers with a tool for assessing health professionals' attitudes towards interprofessional learning at practice level, community health partnership level or at a national level of education and training. Significant differences between professional groups should be taken into account in designing any interprofessional learning programme.

Analysis of Variance↗
PubMed2006

Pathogenomic sequence analysis of Bacillus cereus and Bacillus thuringiensis isolates closely related to Bacillus anthracis.

Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis are closely related gram-positive, spore-forming bacteria of the B. cereus sensu lato group. While independently derived strains of B. anthracis reveal conspicuous sequence homogeneity, environmental isolates of B. cereus and B. thuringiensis exhibit extensive genetic diversity. Here we report the sequencing and comparative analysis of the genomes of two members of the B. cereus group, B. thuringiensis 97-27 subsp. konkukian serotype H34, isolated from a necrotic human wound, and B. cereus E33L, which was isolated from a swab of a zebra carcass in Namibia. These two strains, when analyzed by amplified fragment length polymorphism within a collection of over 300 of B. cereus, B. thuringiensis, and B. anthracis isolates, appear closely related to B. anthracis. The B. cereus E33L isolate appears to be the nearest relative to B. anthracis identified thus far. Whole-genome sequencing of B. thuringiensis 97-27and B. cereus E33L was undertaken to identify shared and unique genes among these isolates in comparison to the genomes of pathogenic strains B. anthracis Ames and B. cereus G9241 and nonpathogenic strains B. cereus ATCC 10987 and B. cereus ATCC 14579. Comparison of these genomes revealed differences in terms of virulence, metabolic competence, structural components, and regulatory mechanisms.

Amino Acids↗
PubMed2004

Biophysical consequences of remodeling the neutral side chains of rhamnogalacturonan I in tubers of transgenic potatoes.

Two lines of transgenic potato (Solanum tuberosum L.) plants modified in their cell wall structure were characterized and compared to wild type with regard to biomechanical properties in order to assign functional roles to the particular cell wall polysaccharides that were targeted by the genetic changes. The targeted polymer was rhamnogalacturonan I (RG-I), a complex pectic polysaccharide comprised of mainly neutral oligosaccharide side chains attached to a backbone of alternating rhamnosyl and galacturonosyl units. Tuber rhamnogalacturonan I molecules from the two transformed lines are reduced in linear galactans and branched arabinans, respectively. The transformed tuber tissues were found to be more brittle when subjected to uniaxial compression and the side-chain truncation was found to be correlated with the physical properties of the tissue. Interpretation of the force-deflection curves was aided by a mathematical model that describes the contribution of the cellulose microfibrils, and the results lead to the proposition that the pectic matrix plays a role in transmitting stresses to the load-bearing cellulose microfibrils and that even small changes to the rheological properties of the matrix have consequences for the biophysical properties of the wall.

Kinetics↗
PubMed2004

Revalidation for general practitioners: randomised comparison of two revalidation models.

OBJECTIVE: To compare two models of revalidation for general practitioners. DESIGN: Randomised comparison of two revalidation models. SETTING: Primary care in Tayside, Scotland. PARTICIPANTS: 66 Tayside general practitioners (principals and non-principals), 53 of whom completed the revalidation folders. Interventions Two revalidation models: a minimum criterion based model with revalidation as the primary purpose, and an educational outcome model with emphasis on combining revalidation with continuing professional development. MAIN OUTCOME MEASURES: Feasibility and acceptability of each approach and effect on the doctor's continuing professional development. The ability to make a summative judgment on completed models and whether either model would allow patient groups to have confidence in the revalidation process. RESULTS: The criterion model was preferred by general practitioners. For both models doctors reported making changes to their practice and felt a positive effect on their continuing professional development. Summative assessment of the folders showed reasonable inter-rater reliability. CONCLUSIONS: The criterion model provides a practical and acceptable model for general practitioners to use when preparing for revalidation.

Accreditation↗
PubMed2002

Electrochemiluminescence from Os(phen)2(dppene)2+ (phen = 1,10-phenanthroline and dppene = bis(diphenylphosphino)ethene).

The electrochemiluminescence (ECL) of Os(phen)2(dppene)2+ (phen = 1,10-phenanthroline and dppene = bis(diphenylphosphino)ethene) is reported in mixed CH3CN/H2O (50:50 v/v) and aqueous (0.1 M KH2PO4) solutions with tri-n-propylamine (TPrA) as an oxidative-reductive coreactant. ECL efficiencies (phi(ecl) = photons emitted/redox event) of 2.0 in aqueous, and 0.95 in mixed for Os(phen)2(dppene)2+ were obtained using Ru(bpy)3(2+) (bpy = 2,2'-bipyridine) as a relative standard (phi(ecl) = 1). Photoluminescence (PL) efficiencies of 0.094 and 0.053 were obtained in aqueous and mixed solutions, respectively, as compared to Ru(bpy)3(2+) (phi(em) = 0.042). The ECL spectra were identical to photoluminescence spectra (lambda(max) approximately 584 nm), indicating formation of the same metal-to-ligand (MLCT) excited states in both ECL and PL. The ECL is linear over several orders of magnitude in aqueous and mixed solution, with theoretical detection limits (blank plus three times the standard deviation of the noise) of 16.9 nM in H2O and 0.29 nM in CH3CN/H2O (50:50 v/v).

Journal Article↗
PubMed2002

Green electrochemiluminescence from ortho-metalated tris(2-phenylpyridine)iridium(III).

The electrochemiluminescence (ECL) of Ir(ppy)3 (ppy = 2-phenylpyridine) is reported in acetonitrile (CH3CN), mixed CH3CN/H20 (50:50 v/v), and aqueous (0.1 M KH2PO4) solutions with tri-n-propylamine as an oxidative-reductive coreactant. ECL efficiencies (phi(ecl), photons emitted per redox event) of 0.00092 in aqueous, 0.0044 in mixed, and 0.33 in CH3CN solutions for Ir(ppy)3 were obtained using Ru(bpy)3(2+) (bpy = 2,2'-bipyridine) as a relative standard (phi(ecl) = 1). Photoluminescence (PL) efficiencies of 0.039, 0.050, and 0.069 were obtained in aqueous, mixed, and acetonitrile solutions, respectively, compared to Ru(bpy)3(2+) (phi(em) = 0.042). The ECL spectra were identical to photoluminescence spectra (lambda(max) approximately equal to 517 nm), indicating formation of the same metal-to-ligand (MLCT) excited states in both ECL and PL. The ECL is linear over several orders of magnitude in mixed and acetonitrile solution with theoretical detection limits (blank plus three times the standard deviation of the noise) of 1.23 nM in CH3CN and 0.23 microM in CH3CN/ H20 (50:50 v/v).

Journal Article↗
PubMed2002

Effects of electron withdrawing and donating groups on the efficiency of tris(2,2'-bipyridyl)ruthenium(II)/tri-n-propylamine electrochemiluminescence.

The effects of electron withdrawing and electron donating groups on the electrochemiluminescent (ECL) properties of tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3(2+) where bpy = 2,2'-pyridine) are reported. The electrochemistry, photophysics and ECL of (bpy)2Ru(DC-bpy)2+, and (bpy)2Ru(DM-bpy)2+ (DC = 4,4'-dicarboxy-2,2'-bipyridine; DM = 4,4'-dimethyl-2,2'-bipyridine) have been studied relative to Ru(bpy)3(2+) in 50:50 (v/v) acetonitrile(CH3CN):H2O (0.1 M KH2PO4), and aqueous solutions. Furthermore, the effects of Triton X-100 (polyethylene glycol tert-octylphenyl ether) on the electrochemical, spectroscopic and ECL properties of these compounds are reported. The anodic oxidation of Ru(bpy)3(2+), (bpy)2Ru(DC-bpy)2+, and (bpy)2Ru(DM-bpy)2+ produces ECL in the presence of tri-n-propylamine (TPrA) in all solvent systems. ECL efficiencies (phi(ecl), photons produced per redox event) of 0.73 and 0.84 for (bpy)2Ru(DC-bpy)2+, and (bpy)2Ru(DM-bpy)2+ were obtained in aqueous buffered solution, using Ru(bpy)3(2+) as a relative standard (phi(ecl) = 1.0). Addition of 0.4 mM Triton X-100 results in a greater than 2-fold increase in ECL efficiences (i.e., 3.8, 2.4 and 2.3 for Ru(bpy)3(2+), (bpy)2Ru(DC-bpy)2+, and (bpy)2Ru(DM-bpy)2+, respectively) using aqueous Ru(bpy)3(2+) containing no surfactant as standard (phi(ecl) = 1.0). ECL efficiencies of 27.4, 16.5 and 26.1 were found in 50:50 (v/v) CH3CN:H2O (0.1 M KH2PO4) for Ru(bpy)3(2+), (bpy)2Ru(DC-bpy)2+, and (bpy)2Ru(DM-bpy)2+, respectively, using aqueous Ru(bpy)3(2+) containing no surfactant as standard (phi(ecl) = 1.0). Detailed studies support adsorption of surfactant on the electrode surface, thus facilitating TPrA and ruthenium oxidation.

Journal Article↗
PubMed2002

Electrochemiluminescence in aqueous solution of a ruthenium(II) bipyridyl complex containing a crown ether moiety in the presence of metal ions.

Changes in electrochemiluminescence (ECL) properties of a ruthenium polyazine compound containing a crown-ether moiety have been investigated in aqueous buffered solution. The electrochemistry, photophysics and ECL of (bpy)2Ru(AZA-bpy)2+ [bpy = 2,2'-bipyridine; AZA-bpy = 4-(N-aza-18-crown-6-methyl-2,2'-bipyridine)] in the presence of Pb2+, Hg2+, Cu2+ and Ag+ are reported. Oxidation of (bpy)2Ru(AZA-bpy)2+ produces ECL in the presence of tri-n-propylamine (TPrA; 0.2 M KH2PO4). Increases in ECL efficiency (photons generated per redox event) greater than 2-fold have been observed that depend on both the concentration and nature of the metal ion, allowing the determination of ions not directly involved in the ECL reaction sequence.

Journal Article↗
PubMed2002

Influence of plasminogen deficiency on the contribution of polymorphonuclear leucocytes to fibrin/ogenolysis: studies in plasminogen knock-out mice.

Plasminogen knock-out (PG(-/-)) mice provide an unique opportunity for the study of alternative mediators of fibrinolysis. Polymorpho-nuclear leucocytes (PMNs) contain non-plasmin fibrinolytic proteases, however the degree to which these cells contribute to fibrin(ogen) degradation in these animals is not known. Thrombi were generated in carotid arteries and jugular veins of PG(-/-) and wild type (PG(+/+)) mice following adventitial application of a 20% ferric chloride solution. PMNs, identified histologically on H&E staining and by immunohistochemistry using anti-mouse PMN RB6-8C5 antibody, accumulated within the thrombus by 6 h after the injury and peaked at 24 h. There was significantly greater retention of PMNs within the thrombi of PG(-/-) mice from 48 to 72 h than in the PG(+/+) controls (at 72 h: PG(-/-)255 +/- 41 cell/mm(2) (n = 5), PG(+/+) 61 +/- 10 cell/mm(2) (n = 5), p<0.01 in the arterial thrombi; PG(-/-) 252 +/- 50 cell/mm(2) (n = 5), PG(+/+) 100 +/- 36 cell/mm(2) (n = 5), p<0.05 in the venous thrombi), providing potential for more PMN derived fibrinolytic enzymes to be present at late times after a thrombotic challenge in PG(-/-) mice relative to the PG(+/+) controls. Intact PMNs were elicited from the peritoneal cavities of PG(-/-) and PG(+/+) mice following 4% thioglycolate stimulation. In vitro studies showed PMNs from PG(-/-) mice to release greater quantities of 10% trichloroacetic acid (TCA)-soluble fibrinopeptides from I(125)-labeled fibrinogen, than cells from PG(+/+) controls although these differences did not become apparent until after 24 h of incubation (at 72 h incubation: PG(-/-) 918 n/10 x 10(6) cells/0.5 ml, PG(+/+) 589 ng/10 10(6) cells/0.5 ml p = 0.005). Furthermore, autoradiographic analysis of the I(125)-labeled fibrinogen degradation products showed the cleavage pattern by PG(-/-) PMNs to be distinct from that produced by PG(+/+) PMNs. These data suggest that a relatively greater role for PMNs-initiated fibrinolysis exists in the setting of plasminogen deficiency, although this prominence only becomes evident more than 24 h after the thrombotic insult. In addition, mechanisms responsible for the process in PG(-/-) mice may be distinct from those primarily responsible for the process in PMNs from PG(+/+) mice.

Animals↗