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Biomedical subjects

A Shepherd

Publications and source records attributed to A Shepherd.

At least 19 recordsLinked to original sources
PubMed1998

HTA as a framework for task analysis.

The motivation for this paper is to review the status of Hierarchical Task Analysis (HTA) as a general framework for examining tasks, including those for which cognitive task analysis methods might be assumed to be necessary. HTA is treated as a strategy for examining tasks, aimed at refining performance criteria, focusing on constituent skills, understanding task contexts and generating useful hypotheses for overcoming performance problems. A neutral and principled perspective avoids bias and enables the analyst to justify using different analytical methods and develop hypotheses as information is gained about the task. It is argued that these considerations are equally valid when examining tasks that are assumed to contain substantial cognitive elements. Moreover, examining cognition within the context of a broader task helps to situate cognition within the network of actions and decisions that it must support, as well as helping to establish where effort in cognitive task analysis is really justified.

Cognition↗
PubMed1998

Enhancing the usability of a task analysis method: a notation and environment for requirements specification.

This paper presents a notation and computer-based tool for the Sub-Goal Template (SGT) method, a task-analytic approach to specifying information requirements. In particular, it focuses upon the ergonomic redesign of a notation used in the SGT method for specifying contingent sequences in operators' tasks. Two experiments are reported in which two notations for redescribing sequences that involve making a choice between task alternatives are compared: a disjunctive form (Either ... or ...)-used in the original SGT scheme, and a conditional form with a redundant negative (If ... then ... if not ...), which has been promoted as a notation for capturing procedural sequences in computer programming. In experiment 1, performance with the conditional notation was better than with the disjunctive notation for redescribing simple and moderately complex task plans, although there was no difference for the most complex task plans. In experiment 2, a computer environment for specifying task plans using the SGT method was compared with a paper-based equivalent. In general, the computer environment was found to be easier to use and led to greater accuracy in plan redescription, although it was slower perhaps as a result of the constraints that it placed on participants. This paper argues for the necessity of ergonomic design in developing notations and tools to support task analysis methods.

Computers↗
PubMed1997

Additional antianginal and anti-ischemic efficacy of mibefradil in patients pretreated with a beta blocker for chronic stable angina pectoris.

This study assessed the safety, tolerability, and efficacy of mibefradil when added to beta-blocker monotherapy in patients with chronic stable angina pectoris. Two hundred five patients were randomized to receive double-blind treatment with either placebo (n = 70), mibefradil 25 mg (n = 67), or mibefradil 50 mg (n = 68) for 2 weeks. Exercise tolerance tests (ETTs) were performed at the end of the run-in (baseline) and double-blind treatment periods, and patients maintained an anginal diary. Compared with placebo, treatment with mibefradil 50 mg resulted in significant increases in exercise duration (36 +/- 51 seconds; p = 0.036), time to onset of angina (48 +/- 65 seconds; p = 0.002), and time to persistent 1-mm ST-segment depression (47 +/- 77 seconds; p = 0.004). Greater reductions in heart rate, blood pressure, and the rate-pressure product were more apparent at each stage of the ETT in the 50-mg mibefradil group than in the placebo group. Daily treatment with mibefradil 50 mg was associated with a significant decrease in the number of weekly anginal attacks (-2.1 +/- 4.0, p = 0.020) compared with placebo. The addition of mibefradil to existing beta-blocker therapy was well tolerated. Dizziness was the most frequently reported adverse event in the mibefradil 50-mg dose, and occurred with an incidence of 4.4%. The addition of mibefradil 50 mg, administered once daily, to patients on stable beta-blocker therapy produced additive antianginal and anti-ischemic effects and was well tolerated.

Adrenergic beta-Antagonists↗
PubMed1996

Pertussis.

Explore the source record for details and available documents.

Adolescent↗
PubMed1995

Resuscitation training.

All physicians, dentists, nurses and health care personnel should be adequately and regularly trained in cardiopulmonary resuscitation. Guidelines for acquiring the necessary skills in basic and advanced life support are now available.

Cardiopulmonary Resuscitation↗
PubMed1993

Oestriol in the treatment of postmenopausal urgency: a multicentre study.

UNLABELLED: Oestrogen deficiency in postmenopausal women is thought to be important in the genesis of lower urinary tract symptoms, in particular the 'urge syndrome'. Evidence to support the use of oestrogen therapy in symptomatic postmenopausal women is, however, limited. Oestriol is a weak, naturally occurring oestrogen that may be beneficial to the urogenital tissues without stimulating the endometrium. We have investigated the use of oestriol in the treatment of postmenopausal sensory and motor urge incontinence. MATERIALS AND METHODS: A double-blind, placebo-controlled, randomised, multicentre study of 3 mg oral oestriol/day for 3 months in the treatment of women with urge incontinence was undertaken. RESULTS AND CONCLUSIONS: Sixty-four women were recruited into the study. Although oestriol produced both subjective and objective improvement in lower urinary tract function, it was not significantly better than placebo. Some of the difficulties of running a multicentre study were encountered.

Double-Blind Method↗
PubMed1992

Organising a continence advisory service.

Modern surgical techniques have greatly improved the treatment of incontinence, but there remains a large number of patients for whom conservative management will be necessary. This paper reports the appointment of a continence adviser 10 years ago, and describes the subsequent development of a District Continence Advisory Service. Experience has shown that this appointment is essential, not only in terms of facilitating the service, but also as a means of ensuring cost efficiency.

Community Health Nursing↗
PubMed1989

Effects of norepinephrine infused in the paraventricular hypothalamus on energy expenditure in the rat.

The metabolic effects of norepinephrine (NE), when infused into the paraventricular nucleus of the hypothalamus (PVN), were examined using indirect calorimetry. In two separate experiments, it was found that NE infused into the PVN reduced energy expenditure in freely moving rats. While NE also reduced motor activity, these reductions were not statistically significant. Reductions in voluntary motor activity were not necessary for a reduction in energy expenditure, as NE still reduced energy expenditure in rats that were lightly sedated. Clonidine, but not L-phenylephrine, mimicked the hypometabolic effect of NE, suggesting an action at alpha 2 receptors. Infusions of NE were also found to increase blood glucose shortly after infusion, although the specificity of this effect is questionable. Taken together, these data suggest that activation of noradrenergic neurons within the PVN results in a metabolic shift towards energy conservation.

Animals↗
PubMed1984

Effect of dehydroepiandrosterone on growth in lean and obese Zucker rats.

Several studies were undertaken to determine the effect of dehydroepiandrosterone (DHEA) on growth in Zucker rats. In experiment 1, 3 weeks of DHEA treatment in lean rats resulted in decreased body weight gain in comparison to control rats. In experiment 2, both lean and obese rats were treated with DHEA from 6 to 21 weeks of age. Significant decreases in body weight were found for both lean and obese DHEA-treated rats. The food efficiency ratio (FER) was significantly decreased in both DHEA-treated groups. Significant decreases in parametrial and retroperitoneal fat pads were found in both lean and obese DHEA-treated rats. This was primarily attributed to a decrease in fat cell number in lean rats and to decreases in both number and size of fat cells in obese rats. In experiment 3 obese female rats were treated with DHEA from 6 to 21 weeks of age followed by 15 weeks with DHEA removed from the diet. Significantly more weight was gained by the rats previously treated than by the control rats, but body weight remained significantly lower than in the control groups. These data indicate DHEA has an effect on altering body weight and body fat in lean and obese Zucker rats.

Adipose Tissue↗
PubMed1984

Metabolic alterations after dehydroepiandrosterone treatment in Zucker rats.

Dehydroepiandrosterone (DHEA) is a known noncompetitive inhibitor of glucose-6-phosphate dehydrogenase (G6PD). In the present investigation, the effects of chronic DHEA treatment on G6PD and several other enzymes involved in lipid metabolism were examined in lean and obese Zucker rats. Significant decreases in body weight were found in DHEA-treated rats in comparison with nontreated rats. In lean rats, DHEA treatment did not decrease either liver or adipose tissue G6PD and fatty acid synthetase activity, but malic enzyme activity was increased. In obese rats, decreased liver and adipose tissue G6PD and fatty acid synthetase activities were found. Malic enzyme activity in liver of obese DHEA rats was increased but not in adipose tissue. Adipose tissue lipoprotein lipase activity was decreased in both lean and obese DHEA rats. Serum insulin in obese DHEA rats was also decreased compared with control obese rats. These results indicate that the inhibition of G6PD may not be the mechanism of action of the antiobesity effect of DHEA. However, the metabolic effects of DHEA seen in obese rats may contribute to its antiobesity action.

Adipose Tissue↗
PubMed1982

Simple practical techniques in the management of urinary incontinence.

Surgery for incontinence should be reserved for specific indications where its value as a primary treatment has been proven. Otherwise surgery should not be employed until a wide range of conservative treatments have been tried and have failed. The conservative methods of management outlined below include "bladder training' using frequency/volume charts to monitor, and alter, the pattern of micturition and number of episodes of incontinence, re-education of the pelvic floor muscles, intermittent self-catheterization, hormone replacement therapy, regulation of fluid intake and bowel habit, discriminate use of diuretics and hypnotics and adjustments to domestic conditions.

Electric Stimulation Therapy↗
PubMed1981

Determinants of response to intravenous hydralazine in hypertension.

There is marked interindividual variation in hypotensive response to intravenous hydralazine (H). We examined the determinants of response in patients with hypertension. After a single intravenous dose of 0.3 mg/kg H, response was correlated independently (r = 0.8364) with both predrug blood pressure and acetylator index (AI). Intravenous dose ranging studies showed that response also depended on the amount of H in the systemic circulation. Although plasma H levels depend on AI after oral doses, this is not so after intravenous administration. AI must therefore affect response to H by an alternative, presumably nonmetabolic mechanism which, not related to AI, perhaps indicating specificity of this effect for H. These data reinforce the potential usefulness of determining AI before giving H to a patient.

Acetylation↗
PubMed1980

Acute duodenal ulceration in children.

Seven cases of acute duodenal ulcer in Papua New Guinea children have been treated personally over a period of 14 years. All had bled, six seriously enough to threaten life, while in five cases laparotomy revealed unsuspected perforation. Aspirin and antimalarials may have been causal in two children. In three others there was an associated illness, but no common cause could be found to explain all cases. Operative treatment recommended is suture control of bleeding, plus vagotomy and pyloroplasty as for an adult with similar presentation.

Acute Disease↗