Biomedical subjects

David Rogers

Publications and source records attributed to David Rogers.

11 recordsLinked to original sources

PubMed2007

Resistance and cross-resistance to imidacloprid and thiamethoxam in the Colorado potato beetle Leptinotarsa decemlineata.

One of the major challenges in managing the Colorado potato beetle, Leptinotarsa decemlineata (Say) is its remarkable ability to develop resistance to virtually every insecticide that has ever been used against it. Resistance is particularly common throughout northeastern USA as far north as Maine. The first instances of resistance to imidacloprid have already been reported from several locations in New York, Delaware and southern Maine. Rotating insecticides with different modes of action may delay insecticide resistance, but successful implementation of this technique depends on a good understanding of resistance and cross-resistance patterns in populations of target pests. LC(50) values were measured for imidacloprid and thiamethoxam in Colorado potato beetle populations from a variety of locations in the USA and Canada using diet incorporation bioassays. The field performance of imidacloprid, thiamethoxam and clothianidin against imidacloprid-resistant beetles on a commercial potato farm in southern Maine was also evaluated. Correlation between LC(50) values for imidacloprid and thiamethoxam was highly significant, even when populations previously exposed to thiamethoxam were excluded from the analysis. There was no statistically detectable difference in the LC(50) values between populations exposed to both insecticides and to imidacloprid alone. Applications of neonicotinoid insecticides at planting delayed build-up of imidacloprid-resistant beetle populations on field plots by 1-2 weeks but failed to provide adequate crop protection. Consistently with bioassay results, there was also substantial cross-resistance among the three tested neonicotinoid insecticides. Results of the present study support the recommendation to avoid rotating imidacloprid with thiamethoxam as a part of a resistance management plan.

Animals↗

PubMed2006

Cheminformatics analysis and learning in a data pipelining environment.

Workflow technology is being increasingly applied in discovery information to organize and analyze data. SciTegic's Pipeline Pilot is a chemically intelligent implementation of a workflow technology known as data pipelining. It allows scientists to construct and execute workflows using components that encapsulate many cheminformatics based algorithms. In this paper we review SciTegic's methodology for molecular fingerprints, molecular similarity, molecular clustering, maximal common subgraph search and Bayesian learning. Case studies are described showing the application of these methods to the analysis of discovery data such as chemical series and high throughput screening results. The paper demonstrates that the methods are well suited to a wide variety of tasks such as building and applying predictive models of screening data, identifying molecules for lead optimization and the organization of molecules into families with structural commonality.

Anti-Infective Agents↗

PubMed2006

Supraclavicular lymph node: incidence of unsuspected metastatic prostate cancer.

An uncommon presentation of prostate carcinoma to the supraclavicular lymph nodes is herein reviewed. With prompt diagnosis and treatment, patient survival can be extended. A high index of suspicion is necessary to make the diagnosis. The clinical features of four cases involving metastatic prostate carcinoma will be discussed.

Adenocarcinoma↗

PubMed2005

Using extended-connectivity fingerprints with Laplacian-modified Bayesian analysis in high-throughput screening follow-up.

This article describes the use of a combination of extended-connectivity fingerprints (ECFPs) and Laplacian-modified Bayesian analysis in a study of the inhibition of Escherichia coli dihydrofolate reductase. The McMaster High-Throughput Screening Lab at McMaster University proposed a competition to predict the hits in a separate test set of 50,000 compounds. Although the problem seemed best approached with 3D methods, the authors show that 2D methods offer surprisingly competitive results with a low computational cost.

Algorithms↗

PubMed2005

Risk of acute myeloid leukemia and myelodysplastic syndrome in trials of adjuvant epirubicin for early breast cancer: correlation with doses of epirubicin and cyclophosphamide.

PURPOSE: We reviewed follow-up of patients treated in 19 randomized trials of adjuvant epirubicin in early breast cancer to determine incidence, risk, and risk factors for subsequent acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). PATIENTS AND METHODS: The patients (N = 9,796) were observed from the start of adjuvant treatment (53,080 patient-years). Cases of AML or MDS (AML/MDS) were reported, with disease characteristics. Incidence and cumulative risk were compared for possible risk factors, for assigned regimens, and for administered cumulative doses of epirubicin and cyclophosphamide. RESULTS: In 7,110 patients treated with epirubicin-containing regimens (92% of whom also received cyclophosphamide), 8-year cumulative probability of AML/MDS was 0.55% (95% CI, 0.33% to 0.78%). The risk of developing AML/MDS increased in relation to planned epirubicin dose per cycle, planned epirubicin dose-intensity, and administered cumulative doses of epirubicin and cyclophosphamide. Patients with administered cumulative doses of both epirubicin and cyclophosphamide not exceeding those used in standard regimens (</= 720 mg/m(2) and </= 6,300 mg/m(2), respectively) had an 8-year cumulative probability of developing AML/MDS of 0.37% (95% CI, 0.13% to 0.61%) compared with 4.97% (95% CI, 2.06% to 7.87%) for patients administered higher cumulative doses of both epirubicin and cyclophosphamide. CONCLUSION: Patients treated with standard cumulative doses of adjuvant epirubicin (</= 720 mg/m(2)) and cyclophosphamide (</= 6,300 mg/m(2)) for early breast cancer have a lower probability of secondary leukemia than patients treated with higher cumulative doses. Increased risk of secondary leukemia must be considered when assessing the potential benefit to risk ratio of higher than standard doses.

Adult↗

PubMed2005

Perceptions of operating room tension across professions: building generalizable evidence and educational resources.

BACKGROUND: Effective team communication is critical in health care, yet no curriculum exists to teach it. Naturalistic research has revealed systematic patterns of tension and profession-specific interpretation of operating room team communication. Replication of these naturalistic findings in a controlled, video-based format could provide a basis for formal curricula. METHOD: Seventy-two surgeons, nurses, and anesthesiologists independently rated three video-based scenarios for the three professions' level of tension, responsibility for creating tension and responsibility for resolution. Data were analyzed using three-way, mixed-design analyses of variance. RESULTS: The three professions rated tension levels of the various scenarios similarly (F=1.19, ns), but rated each profession's responsibility for creating (F=2.86, p<.05) and resolving (F=1.91, p<.01) tension differently, often rating their profession as having relatively less responsibility than the others. CONCLUSIONS: These results provide an evidence base for team communications training about tension patterns, disparity of professional perspectives, and implications for team function.

Anesthesiology↗

PubMed2005

The effects of group dynamics on resident progress committee deliberations.

BACKGROUND: Prior investigations suggest that resident progress decisions by committee provide a broader perspective on performance and result in less grade inflation. There is countervailing concern that group dynamics may compromise quality of progress decisions. PURPOSE: To determine whether and how group dynamics compromise decision making about resident progress. METHODS: Researchers recorded and analyzed participant comments during a resident progress committee meeting. End-of-rotation (EOR) evaluations were analyzed and compared to progress committee meeting results. RESULTS: EOR and progress committee comments were similar in content. The ratio of specific to general comments was higher for EOR evaluations (5:1) than for progress committee meetings (2:1). EOR evaluation comments provided more supporting evidence for assertions. Individual progress committee participants did not dominate discussion or sway decision making. Participant progress committee meeting comments were consistent with their EOR comments failing to support the presence of progress committee meeting "feeding frenzies." CONCLUSIONS: Results suggest that progress committee meeting group dynamics do not seriously compromise the validity of resident progress decisions.

Employee Performance Appraisal↗

PubMed2004

Classification of kinase inhibitors using a Bayesian model.

The use of Bayesian statistics to model both general (multifamily) and specific (single-target) kinase inhibitors is investigated. The approach demonstrates an alternative to current computational methods applied to heterogeneous structure/activity data sets. This approach operates rapidly and is readily modifiable as required. A generalized model generated using inhibitor data from multiple kinase classes shows meaningful enrichment for several specific kinase targets. Such an approach can be used to prioritize compounds for screening or to optimally select compounds from third-party data collections. The observed benefit of the approach is finding compounds that are not structurally related to known actives, or novel targets for which there is not enough information to build a specific kinase model. The general kinase model described was built from a basis of mostly tyrosine kinase inhibitors, with some serine/threonine inhibitors; all the test cases used in prediction were also on tyrosine kinase targets. Confirming the applicability of this technique to other kinase families will be determined once those biological assays become available.

Artificial Intelligence↗

PubMed2004

Partial duplication 2p as the sole abnormality in two cases with anencephaly.

Anencephaly/NTD has been observed in aneuploid and non-aneuploid individuals. We present two cases of anencephaly diagnosed prenatally with partial duplication of the short arm of chromosome 2 as the sole abnormality. The absence of aneuploidy involving other regions of the genome in these cases, further substantiates suggestions of the existence of a gene or genes on the short arm of chromosome 2 critical in the development of the central nervous system.

Anencephaly↗

PubMed2002

Transmission of crayfish plague.

Two possible means of transmission of crayfish plague were investigated: via fish (as vectors), and via crayfish (as hosts or vectors when dead). The crayfish transmission experiments focussed on both the viability of the fungus in dead crayfish when kept in simulated field conditions, and on the treatments which kill viable forms of Aphanomyces astaci within the recently dead host (cadaver). It was found that A. astaci remains viable for 5 d, and possibly longer in crayfish kept in water at 21 degrees C after dying of crayfish plague. Heating (boiling for 1 min) was the quickest way of decontaminating crayfish cadavers. Freezing took considerably longer: after 48 h at -20 degrees C, viable stages were still present. It was also found that A. astaci is unlikely to survive passage of the gastrointestinal tract of either mammals or birds as no viable stages were found after 12 h at 37 degrees C. Two basic modes of transmission of crayfish plague via fish were investigated: (1) after passage of initially viable forms of A. astaci through the digestive tract of fish and (2) via fish skin. If A. astaci was fed to fish as infected abdominal cuticle, it was still viable after passage through the gastrointestinal tract. When pure mycelium or spores were fed to fish there was no indication of viable forms of A. astaci after passage through the gastrointestinal tract. Transmission via fish skin was not observed under the experimental conditions applied. The results on fish as vectors have practical importance for fish transport and stocking because the present study shows that there is a risk of transmission of crayfish plague via fish faeces. The investigation of crayfish as vectors delivers methods that could be used for treatment of crayfish imported for human consumption into crayfish-plague-free areas. This application is particularly important for the importation of American crayfish, which are in general suspected to carry A. astaci in their cuticle.

Animals↗

PubMedDate not supplied

Bedside clinical guidelines: the missing link.

Clinical guidelines for acute general (adult) medicine, general (adult) surgery, nursing and acute paediatrics, for use at the bedside, were developed over 10 years in North Staffordshire. The guidelines have been adopted by 15 other hospitals, all members of the Bedside Clinical Guidelines Partnership. The guidelines include advice on clinical management, prescribing aids, and practical procedures. Recommendations are validated against published evidence, and provide the 'missing link' between this evidence and practical clinical care, by taking current consensus into account. The guidelines are clear, brief and specific, informing and guiding the actions of clinicians. Annual updating involves checking evidence and compatibility with national recommendations, and soliciting feedback from users to eliminate ambiguity or misunderstanding. Continued human effort and financial investment are required to ensure that the guidelines remain a 'living' document.

Adult↗