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Biomedical subjects

D R Thompson

Publications and source records attributed to D R Thompson.

At least 19 recordsLinked to original sources
PubMed2000

Determining chest pain patients' suitability for transfer to a general ward following admission to a cardiac care unit.

The objective of this study was to assess the performance of a consensus-derived decision algorithm in determining chest pain patients' suitability for early transfer to a lower dependency ward by predicting complications. The sample comprised 516 patients with chest pain presumed to be cardiac in origin, admitted to a cardiac care unit (CCU) in northern England from the community or from the accident and emergency department. A decision algorithm was designed following a review of the literature and amended to take into account a clinical consensus of consultant physicians. Patients were assessed on admission by CCU nurses using the algorithm, and 'triage' decisions recorded (keep on CCU or suitable for early transfer to a general ward). Admission ECGs (electrocardiographs) and baseline clinical data were recorded independently by a researcher 'blinded' to actual clinical course, and applied to the algorithm using statistical software. On discharge or death, patients' case notes were retrieved and the hospital course examined for death or severe complications. Performance of the algorithm and CCU nurses were compared for sensitivity, specificity, positive predictive value and negative predictive value. The main outcome measures were death or severe complications occurring during hospitalization, and during the first 2 days following CCU admission. While sensitivity of both the algorithm (0.98) and CCU nurses (0.95) was high, specificity was low in both groups (0.11 and 0.21, respectively), making it unlikely that the algorithm would prove useful in clinical practice. Further studies are required to develop the optimal triage tool for the assessment of patients with acute chest pain.

Aged↗
PubMed1999

Effect of omeprazole paste on gastric acid secretion in horses.

In a multicentre trial, 13 cannulated horses were treated orally once daily with a paste that delivered omeprazole at a dose of 4 and 5 mg/kg bwt in a 2-period crossover design to evaluate steady state gastric acid suppression. In each period, basal (unstimulated) and pentagastrin-stimulated gastric output were evaluated at 5-8 h after 5 doses, at 13-16 h after 10 doses, and at 21-24 h after 15 doses. Baseline data for gastric acid secretion were collected once for each horse in the month prior to initiation of omeprazole treatment. The inhibition of gastric acid secretion relative to baseline values, following treatment with omeprazole, were calculated and expressed as per cent. Pharmacokinetic data were also collected in this trial. At 4 mg/kg bwt, the oral paste formulation of omeprazole inhibited both basal and pentagastrin-stimulated gastric acid secretion by 99% at 5-8 h after treatment and by 83% (basal) and 90% (pentagastrin-stimulated) at 21-24 h. Inhibition following the administration of omeprazole at a dose of 5 mg/kg bwt was not significantly greater than when given at 4 mg/kg bwt. The results from this study could possibly lead to the development of an effective and practical antisecretory treatment of ulcer disease in horses.

Administration, Oral↗
PubMed1998

Evidence for the effectiveness of cardiac rehabilitation.

Cardiac rehabilitation is a relatively recent development and, though it is increasingly being recognized as an important part of comprehensive cardiac care, there remains some scepticism regarding its effectiveness and some ignorance of its potential. This article reviews the literature pertaining to the effectiveness of cardiac rehabilitation for patients with coronary heart disease (CHD).

Coronary Disease↗
PubMed1998

A randomized trial comparing Arglaes (a transparent dressing containing silver ions) to Tegaderm (a transparent polyurethane dressing) for dressing peripheral arterial catheters and central vascular catheters.

The purpose of this trial was to prepare for a large randomized trial comparing Arglaes film dressing, a recent innovation containing silver ions, against Tegaderm, a transparent polyurethane dressing. Thirty-one patients admitted to the intensive care unit and requiring the insertion of an arterial line or central venous catheter were recruited into the study. Skin swabs were taken from the insertion sites prior to catheterization and on removal of the intravascular device to measure skin colonization rate between the two dressings. The catheter tips were also cultured on removal to establish if there was a difference between the two groups. No statistical differences were found in bacterial growth between the two dressings.

Adolescent↗
PubMed1998

"Hey, would you like a nice cold cup of lemonade on this hot day?": children's understanding of economic causation.

Three experiments were performed to examine development of understanding of functional relations in economics by children between ages 4 and 10 years. Results of Experiment 1 indicated that preschoolers understood the effects of demand, and 2nd graders also understood the effects of supply, but even 4th graders often failed to demonstrate understanding of the effects of motivation and morality. In Experiment 2, 4th but not 2nd graders proved able to explain how motivation and morality might influence sales when told that these variables had an effect. In Experiment 3, 2nd and 4th graders' evaluations of the plausibility of other children's explanations of effects of motivation and morality showed evidence of understanding, though those of kindergartners did not. The data supported the 3 hypotheses that motivated the experiments: (a) direct links between causes and effects are understood before indirect ones, (b) positive correlations between causes and effects are understood before negative ones, and (c) variables that produce effects are understood before ones that do not.

Child↗
PubMed1998

A versatile microprocessor-based multichannel stimulator for skeletal muscle cardiac assist.

A versatile, microprocessor-based stimulator for skeletal muscle cardiac assist (SMCA) has been designed, constructed, and used in several studies. The stimulator uses multiple bipolar electrodes to deliver arbitrarily specified electrical stimulus sequences to three nerve branches of the latissimus dorsi muscle. The electrodes are electrically isolated to effect regional stimulation of the muscle. The width, amplitude, and interpulse interval of each pulse in the stimulus sequence are independently variable, and the three channels are independently programmable, allowing a wide variety of stimulus patterns. Battery powered units have been used in studies for up to one year. In this paper, the stimulator and sample applications in SMCA are described.

Analog-Digital Conversion↗
PubMed1997

Cardiac rehabilitation services in England and Wales: a national survey.

We sent a short postal questionnaire to 244 centres in England and Wales that admitted patients with cardiac conditions. In total, 199 (81%) of the centres claimed to provide a cardiac rehabilitation service. Of these, 25 were randomly selected as a representative sample and visited in order to obtain detailed information concerning the provision of services. Most (18 (72%)) of the centres had commenced their rehabilitation programme within the previous 5 years, usually at the instigation of interested staff. Patient entry to cardiac rehabilitation programmes was restricted; women (who represented only 15% of attenders), elderly people (excluded in 10 (40%) centres), and those with more complex problems, such as angina or heart failure, were under-represented. The central components of all programmes were education and exercise training but there was a wide range in the quantity and quality of service provision. Most (22 (88%)) programmes were hospital out-patient based, one (4%) was hospital in-patient based, one (4%) was community-based and one (4%) was home-based. The staffing and funding of programmes was variable, with 7 (28%) having no identified funding. There are wide variations in the resources currently available for the rehabilitation of patients with coronary heart disease. There is a need for clearer direction of these services, in particular to determine minimum service provision. Guidelines are necessary to give a framework for this relatively new and rapidly expanding service.

Aged↗
PubMed1997

Effect of simulated rain, coat length and exposure to natural climatic conditions on the efficacy of a topical formulation of eprinomectin against endoparasites of cattle.

A series of five controlled studies involving 114 cattle were conducted in Australia, North America and the United Kingdom to examine the effect of simulated rain, coat length and exposure to natural climatic conditions, on the efficacy of a topical formulation of eprinomectin against nematode parasites of cattle. In all trials infections were induced with a range of bovine nematode species and treatment was applied when the majority of nematodes were mature. In one study, simulated rain was applied to cattle ending one hour before treatment or beginning one, three or six hours after treatment. In a second study cattle had short (1 cm) or long (3-6 cm) haircoats at the time of treatment. Three other studies were conducted using cattle housed indoors or exposed to various natural climatic conditions. Nematode counts were determined using standard techniques and the efficacy of treatment was assessed relative to vehicle-treated controls. Regardless of the timing of simulated rain relative to treatment, eprinomectin was at least 99.9% effective (P < 0.01) against Haemonchus placei, Ostertagia ostertagi. Trichostrongylus axei and Cooperia spp. There were also no differences (p > 0.10) in efficacy between treatment administered to dry or wet cattle, or treatment administered before or after simulated rainfall. Efficacies against O. ostertagi, T. axei, Cooperia ancophora and Dictyocaulus viviparus were > 99.5% (p < 0.01) regardless of the length of the haircoat at the application site. Exposure of treated cattle to sunshine and precipitation had no effect on anthelmintic efficacy (p > 0.10) with efficacies of greater than 99.5% being maintained against H. placei, O. ostertagi (adult and fourth-stage larvae), T. axei, Cooperia spp., Nematodirus helvetianus (adult and inhibited fourth-stage larvae) and Oesophagostomum radiatum. These findings indicate that eprinomectin (500 micrograms/kg) in a topical formulation is a safe and highly effective nematocide for cattle regardless of their coat length and this high level of efficacy is maintained in cattle exposed to a wide variety of climatic conditions.

Administration, Topical↗
PubMed1997

Nematocidal efficacy of eprinomectin, delivered topically, in naturally infected cattle.

OBJECTIVE: To assess the nematocidal efficacy of eprinomectin in naturally infected cattle. ANIMALS: 62 (31 eprinomectin-treated and 31 control) beef mixed-breed or Holstein cattle, either 6 to 11 or 48 to 96 months old. PROCEDURE: Cattle were housed 21 to 27 days before treatment to allow parasites to reach maturity. Animals were grouped by sex, ranked by weight, and randomly assigned to treatment group. Fecal flotation was done to identify cattle with intestinal nematode infections. Treatment groups were: 1--eprinomectin topical vehicle (1 ml/10 kg) and 2--eprinomectin topical solution (1 ml/10 kg). Cattle were euthanatized by replicate on day 14 or 15, and standard procedures were used to recover of pulmonary, abomasal, small intestinal, and large intestinal nematodes. RESULTS: Eprinomectin efficacy across all trials was 100% against adult Trichostrongylus axei, Haemonchus placei, Oesophagostomum radiatum, and Dictyocaulus viviparus, as well a fourth-stage larval Oes radiatum, Ostertagia ostertagi, Nematodirus helvetianus, and Cooperia spp. Efficacy against adult O ostertagi, Cooperia oncophora, C punctata, C surnabada, C spatulata, N helvetianus, Trichuris sp, and Trichuris fourth-stage larvae was 99.9 and 99.8, 99.6, 98.9, 98.3, 99.7, 97.8, and 84.3%, respectively. All results were significant (P < 0.01) except those for C spatulata. Adverse reactions were not observed. CONCLUSION AND CLINICAL RELEVANCE: Eprinomectin is a safe and effective nematocide against naturally acquired nematode infections in cattle when administered at a dosage of 500 micrograms/kg. Milk and meat withholding is not necessary when using this product.

Administration, Topical↗
PubMed1997

Optimizing muscle-to-cardiac timing for aortomyoplasty.

A new surgical approach to support failing hearts is known as aortomyoplasty-a technique in which the latissimus dorsi muscle is wrapped around the aorta and stimulated during cardiac diastole to provide chronic diastolic counterpulsation. We hypothesized that the timing of muscle contraction within the cardiac cycle effects the amount of diastolic augmentation during counterpulsation. In dogs (n = 9, 20-25 kg), the effect of muscle-to-cardiac timing on hemodynamic outcome of aortomyoplasty was measured. Muscle stimulation was initiated at the dicrotic notch and stimulus durations were systematically increased. Mean diastolic aortic pressure was maximized when stimulation terminated at the ensuing R-wave. Peak left-ventricular pressure was minimized when muscle stimulation terminated before the ensuing R-wave. The endocardial-viability ratio (a ratio of aortic diastolic pressure augmentation to left-ventricular pressure reduction) was maximized when stimulus terminated at the ensuing R-wave. Muscle-to-cardiac timing influences the effectiveness of counterpulsation during aortomyoplasty.

Animals↗