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Biomedical subjects

A Grant

Publications and source records attributed to A Grant.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Costing neonatal care alongside the Collaborative ECMO trial: how much primary research is required?

Researchers working on economic evaluations alongside trials have to balance minimising data collection with maximising the ability to measure differences in costs. Using existing data sources may keep the costs of research down, but these data may not be entirely appropriate to the evaluation question. When evaluating technologies in intensive care it is particularly important to be able to classify patients correctly by their resource requirements especially when those requirements vary considerably from day to day. This paper describes and justifies methods for costing the care provided for babies in (one arm of) an on-going multi-centre trial, the Collaborative ECMO trial. This trial is evaluating alternative policies of life support for mature (full term) newborn babies with severe respiratory failure. The most reliable cost information on neonatal intensive care is available from a study, conducted independently from the trial, which has used simple cost apportionment on a large sample of units. By drawing on clinical opinion and carrying out a case note exercise we assessed whether this available information was appropriate to estimate 'baseline' costs for the control group during their initial 'acute' phase of illness. We concluded that the available cost estimates would need to be weighted to reflect the additional costs of drugs and investigations for this group of babies during the acute phase. Multidisciplinary collaboration on trials can help economists and other researchers to balance the requirement for simple cost measurements with more detailed primary research.

Cost-Benefit Analysis↗
PubMedDate not supplied

Odorant response of individual sensilla on the Drosophila antenna.

We have documented odor responses of all morphological classes of sensilla on the surface of the Drosophila antenna: sensilla basiconica, sensilla trichodea, and sensilla coeloconica. Both subtypes of s. basiconica, large and small, respond to odors. S. trichodea fall into different functional types. Type 1 appears narrowly tuned, as it responded only to cis-vaccenyl acetate, believed to be a pheromone. Type 2 responded to trans-2-hexenal and 4-methyl cyclohexanol. These two types of s. trichodea are differentially distributed on the antennal surface, and have dramatically different frequencies of spontaneous action potentials. Likewise, there are multiple types of s. coeloconica. One type if broadly tuned, responding most strongly to a test stimulus of butyric acid, but also to a variety of other odors; it is restricted to the dorso-medial portion of the third antennal segment. A second type gave detectable responses only to trans-2-hexenal. These results demonstrate that all classes of sensilla are olfactory, and they reveal the organizational complexity of the Drosophila olfactory system.

Acetates↗
PubMedDate not supplied

Rationale for and work of the Perinatal Trials Service.

The Perinatal Trials Service provides a service to busy clinicians who wish to mount large simple-in-design randomized trials. The trials aim to identify moderate, but clinically useful, effects of promising treatments for the most important problems in perinatal care. A combination of a flexible five-person core resource and a cadre of staff employed to work on specific trials allows a programme of trials to be conducted successfully and efficiently. The Perinatal Trials Service has three main areas of work: prevention and treatment of immaturity and its consequent morbidity; identification and management of the compromised fetus or baby; and prevention and treatment of maternal morbidity. Examples of projects from each area are described.

Perinatology↗
PubMedDate not supplied

A non-contact mode scanning force microscope optimised to image biological samples in liquid.

Given that biological samples are particularly soft in their natural state and that a liquid is the most difficult operating environment for non-contact mode scanning force microscopy, the development of a scanning force microscope that is optimised to image biological samples in vitro presents significant challenges. The performance of the instrument described here has been optimised for such an application by incorporating magnetic excitation and active-Q control of the cantilever. The application of this instrument has been validated by imaging monolayers of immobilised antibodies in liquid and achieving image qualities comparable to those achieved in air for such samples.

Antibodies, Monoclonal↗
PubMedDate not supplied

Use of evidence in the process of practice change in a clinical team: a study-forming part of the Autocontrol Project.

The Autocontrol Project is concerned with the accessing, processing and communication of high quality information so that a clinical team can make and implement decisions for practice change, and then evaluate if improvement has been achieved. High quality information is used as evidence for change. In this study, we have evaluated how evidence is used by a clinical team to explain an identified problem of inappropriate use of blood gas tests. In an experimental study of the Surgical Intensive Care Unit, video recordings of team meetings of nurses and doctors were undertaken, structured according to a problem-based format. Evidence of current practice patterns derived from the hospital information system, as well as the results of a questionnaire to the unit's staff about knowledge and use of blood gas measurements, were supplied to the participants beforehand. At the second meeting, the output of the first meetings and a summarised analysis of pertinent literature were made available. This second meeting was required to finalise the list of causes of inappropriate blood gas use and propose pragmatic strategies for practice change. The video data of the meetings were coded to analyse the use of evidence, the categories of causes, issues and solutions proposed, and the quality of team interaction. The results indicate that in order to achieve consensus, the team used different types of evidence, including objective evidence of practice patterns, personal experience about direct and indirect organisational influences, and literature-based research evidence of best practice. Furthermore, group dynamics were favoured by the problem-based meeting structure, and a high level of cognitive critiquing between team members was observed. This research suggests that a combination of approaches involving identification of both operational factors (e.g. appropriate access to different types of evidence and meeting structure) and cognitive and behavioural approaches (e.g. ensuring expression of different viewpoints) is needed to support strategic decision-making for practice change in a clinical unit. This combined approach should favourably influence the provision of an effective and efficient evidence support environment for the clinical team.

Blood Gas Analysis↗
PubMedDate not supplied

Difficult cases in heart failure. Novel diagnostic markers in heart failure: an emerging paradigm shift?

The differential diagnosis of dyspnea can be overwhelming in the presence of competing diseases. The recent advent of the peptide marker brain natriuretic peptide has ushered in an era of refined diagnostic capability in heart failure. We present a clinical scenario to illustrate the usefulness of this new biomarker assay in directing appropriate therapy for heart failure. (c)2001 CHF, Inc.

Journal Article↗
PubMedDate not supplied

Fate of fibrinogen in human arterial intima.

Fibrinogen and fibrinogen/fibrin-related antigen (total FRA) was measured in human normal intima and different types of atherosclerotic lesions and mural thrombi. The amount showed marked variation between groups of tissue samples, but within each group there was a significant correlation between levels of total FRA and low density lipoprotein (LDL), suggesting that some common factor must influence their influx or retention. The total FRA were analyzed by gradient sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting with antisera to whole fibrinogen and fragments D and E, and fibrinopeptide A (FPA). All intimal samples (but not thrombi) contained fragment X, the first product of plasmin digestion of fibrinogen, but fragment Y was present in only half the samples, and no core-fragment E containing FPA was detected in any sample, suggesting that fibrinogenolysis is limited. By contrast, all samples contained fragment E, which was negative for FPA, so presumably derived from fibrin; they also contained fragments D-dimer and DY, which are characteristic degradation products of cross-linked fibrin. There were no differences between samples obtained during reconstructive vascular surgery and samples obtained at autopsy, so the patterns appear to represent the steady state. This implies that within the intima there is continuous formation of cross-linked fibrin and continuous fibrinolysis, both processes generating fragments that may have atherogenic properties.

Adult↗