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Biomedical subjects

M Morgan

Publications and source records attributed to M Morgan.

At least 289 records · Page 16Linked to original sources
PubMed1987

Propofol infusion for sedation in the intensive care unit: preliminary report.

Propofol (2,6,di-isopropylphenol) was given by continuous intravenous infusion to provide sedation after cardiac surgery in 30 patients and its effects compared with those of midazolam given to a further 30 patients. Propofol infusion allowed rapid and accurate control of the level of sedation, which was satisfactory for longer than with midazolam. Patients given propofol recovered significantly more rapidly from their sedation once they had fulfilled the criteria for weaning from artificial ventilation and as a result spent a significantly shorter time attached to a ventilator. There were no serious complications in either group. Both medical and nursing staff considered the propofol infusion to be superior to midazolam in these patients. These findings suggest that propofol is a suitable replacement for etomidate and alphaxalone-alphadolone for sedating patients receiving intensive care.

Blood Pressure↗
PubMed1987

Length of stay for common surgical procedures: variation among districts.

Lengths of stay for appendicectomy, inguinal hernia repair and cholecystectomy for the 16 districts in the Northern Regional Health Authority (NRHA) and 15 districts in the South East Thames Regional Health Authority (SETRHA) are examined using data recorded in the Hospital Activity Analysis. Considerable variations exist among districts, with the three longest stay districts for each procedure in NRHA having an age-adjusted length of stay of 113 per cent of the regional average for appendicectomy, 125 per cent for hernia and 115 per cent for cholecystectomy. This resulted in greater than 2000 additional bed days per year being occupied in the three longest stay districts in the NRHA compared with the regional average. The age adjusted length of stay for the three shortest stay districts for each procedure is 83 per cent of the regional average for appendicectomy, 75 per cent for hernia and 85 per cent for cholecystectomy. Similar differences are seen in the SETRHA, and derive from differences in the length of both preoperative and postoperative stay. Explanations for the observed variations are considered in terms of population, organizational and clinical variables.

Adolescent↗
PubMed1987

Detection of moving local density differences in dynamic random patterns by human observers.

The way in which movement enhances target visibility has been investigated by measuring the detectability of the direction of motion of a dot pattern added to a background of dynamic visual noise. When the positions of all the dots were changed randomly from frame to frame, so that there was no dot configuration to define the target area (experiments 1 and 2), the threshold density difference necessary was for direction of motion detection less than 3 dots/frame (between 20% and 50% density difference). The spatial displacement (S) at which optimal detection occurs increased when a target elongated in the direction of motion was used. If S was either larger or smaller than its optimal value, thresholds rose progressively. The rise in threshold when S was smaller than 0.25 deg (the width of the target area) decreased when the target dots had a fixed spatial arrangement (experiment 3). It is suggested that in both fixed and random target configurations there is a grouping of dots with similar trajectories via a global directionally-selective process. The strength of the overall motion signal is greater in the fixed-dot configuration because each target dot has associated with it a vector precisely aligned in the direction of the target motion.

Attention↗
PubMed1987

Measles immunisation: feasibility of a 90% target uptake.

A three part investigation of the factors that might influence uptake of immunisation was carried out in Maidstone Health Authority; this included studies of the computer system and attitudes of parents and professionals. Several problems with immunisation scheduling, information transfer between general practitioners and clinics and the computer centre, and validity of computer information were identified. The attitudes of parents, relatives, and friends were generally favourable, although parents reported a lack of knowledge about the disease and vaccine and lack of advice from professionals. Perceived contraindications to immunisation, particularly a history of measles, were important reasons for non-uptake. Professionals' perceptions of contraindications, however, were at variance with Department of Health and Social Security guidelines and none of the recorded contraindications was valid. Calculations of potential uptake suggest that a 90% target uptake is feasible and recommendations are made for changes in services.

Attitude of Health Personnel↗
PubMed1987

Epidural and intrathecal opioids.

Small doses of epidural and intrathecal opioids produce effective and prolonged analgesia postoperatively, although the quality of analgesia does not differ from when conventional routes are used. The different opioids differ only in the speed of onset and duration of action, and in the incidence of side-effects. 'Minor' complications such as nausea, vomiting, pruritus and retention of urine are relatively common. There is a small incidence of respiratory depression which is delayed for several hours after drug administration and which may be prolonged. It is commoner after morphine and after intrathecal administration, and is also associated with advanced age, concomitant use of other central depressant drugs, respiratory disease and large doses. Because of the potentially lethal nature of this complication, it is recommended that the epidural and intrathecal routes of administration are used only when patients can be closely and constantly observed postoperatively.

Analgesics, Opioid↗
PubMed1987

Parents' attitudes to measles immunization.

A study of a cohort of children in Maidstone Health Authority examined the reasons for the failure to achieve targets for the uptake of measles immunization. Parents were interviewed before they were notified about measles immunization to determine their attitudes, beliefs and intentions regarding measles immunization and a further review was held with those whose child had no record of the immunization by the age of 20 months. The initial interview showed that most parents have a favourable attitude to measles immunization. However, many lacked knowledge, especially about valid contraindications, and claimed not to have received advice from a doctor or health visitor. The most common reasons for non-uptake of measles immunization were: the child had already had measles, concern about contraindications and delay owing to illness. This points to the importance of increasing doctors' and health visitors' knowledge of Department of Health and Social Security guidelines regarding valid contraindications and to the role of health visitors in promoting uptake. However there is also evidence that the gap between actual and target levels of uptake may be less than official figures suggest.

Attitude to Health↗
PubMed1986

Comparison of two routes of chemical administration on the lung adenoma response in strain A/J mice.

This study was undertaken to determine the ability of a series of 19 compounds representing different chemical classes of carcinogens to induce lung tumors in strain A/J mice after either ip or po administration. Aflatoxin B1, dibutylnitrosamine, 1,2-dimethylhydrazine, and methylnitrosourea induced a significant increase in the lung tumor response in both sexes after ip and po administration. Azaserine was active in both sexes only after ip administration. Benzene, 1,2-dibromoethane, and epichlorohydrin, following ip administration, produced significant increases in the tumor response in at least one sex. Aflatoxin B1, azaserine, benzene, 1,2-dibromoethane, dibutylnitrosamine, and epichlorohydrin were more active when given ip than after po administration. In contrast, dimethylhydrazine and methylnitrosourea were more active (in females only) when given po. 2-Acetylaminofluorene, azobenzene, chloroform, 1,4-dioxane, FANFT (N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide), lead subacetate, methylmethanesulfonate, beta-naphthylamine, beta-propiolactone, safrole, and 2,4,6-tri-chlorophenol did not induce lung tumors in strain A/J mice. These data confirm previous observations on the importance of the route of chemical administration on the lung tumor response in strain A mice, and on the inability of the lung tumor bioassay to detect certain liver and bladder carcinogens and unstable alkylating agents.

Adenoma↗
PubMed1986

Irradiation: implications for theories of edge localization.

In a vernier alignment task, observers judged the relative positions of two blurred edges placed one above the other. If the two edges were given the same blur width and contrast polarity, their relative positions were perceived veridically. If the two edges were given different blur widths or opposite contrast polarities, reliable errors in perceived position were revealed, as if each edge were shifted into its dark phase by an amount proportional to its blur. The magnitude of shift varied from zero for sharply defined edges, to over 1 min arc for blurred edges. These illusory shifts in position are consistent with the well-known phenomenon of "irradiation". Implications for current models of edge localization are discussed.

Form Perception↗
PubMed1986

Treatment of intracranial aneurysms by combined proximal ligation and extracranial-intracranial bypass with vein graft.

Seven patients with internal carotid artery aneurysms, and one patient with a middle cerebral artery aneurysm, were managed by combining proximal ligation with an extracranial-intracranial bypass procedure. Five bypasses were done with an interposed vein graft between the external carotid artery and the distal middle cerebral artery (vein graft), and three were superficial temporal-middle cerebral artery bypasses (superficial temporal artery grafts). As demonstrated in postoperative angiograms, all eight patients had patent bypasses with nonfilling of the aneurysm. One patient developed transient dysphasia, but there were no permanent neurological deficits associated with carotid occlusion. Four patients had resolution of their neurological problems, and another three patients improved. The distribution of flow from vein grafts is more extensive than from superficial temporal artery grafts. This offers increased protection against ischemia, and increases the likelihood of internal carotid artery aneurysm thrombosis by reducing the turbulence in the distal internal carotid artery.

Adult↗
PubMed1986

Pseudoaneurysm complicating superficial temporal artery-superior cerebellar artery bypass.

A 60-year-old man with vertebrobasilar ischemia unrelieved by anticoagulation was found to have a midbasilar stenosis with an inadequate basilar collateral circulation. He underwent a right superficial temporal-superior cerebellar artery bypass. Following this operation he had a subarachnoid hemorrhage and right third nerve palsy that was due to formation of a pseudoaneurysm at the site of the anastomosis. This aneurysm was managed by ligation of the right superficial temporal artery. Subsequently it became necessary to perform a left superficial temporal artery-superior cerebellar artery bypass because of severe posterior circulation ischemic symptoms.

Cerebellum↗
PubMed1986

Psychosocial support and change in the health status of physically disabled people.

Evidence is presented on the relationship between psychosocial support (social contact and emotional intimacy) and changes in health status (physical, psychosocial and emotional functioning) experienced by 583 adults age 45-75 years living at home with a preexisting physical illness. Data were used from a panel study of physically disabled adults in London, England to provide a test of the buffer and direct effects hypotheses concerning social support and adverse life events. Controlling for age, sex and initial level of health status, the analyses showed that a low level of social contact was associated significantly with deterioration in psychosocial and emotional functioning only in the presence of adverse life events. A similar but non-significant pattern existed for physical functioning. A high level of social contact had a more protective effect on the physical functioning of respondents with arthritis or heart trouble who also reported depression, except among women age 45-64. Level of emotional intimacy was not a significant influence on reported health status change. Confiding relationships do not appear important for adults with preexisting illnesses who are not at significant risk of developing stress-related conditions. Social participation outside the home would help to reduce deterioration in psychosocial and emotional functioning, important outcomes for improving and maintaining quality of life.

Aged↗
PubMed1986

Typhlitis in acute childhood leukaemia: radiological features.

Typhlitis is a necrotising inflammation of the caecum usually found in acute leukaemic patients on chemotherapy. We described the radiological features of two children with this complication. The first was diagnosed by an enema using water-soluble contrast medium and the second by ultrasound and computed tomography (CT). A water-soluble contrast medium enema is considered diagnostic in this clinical context and excludes intussusception and, often, appendicitis. Ultrasound showed a rounded mass with dense central echoes and a wider hypoechoic periphery. Computed tomography showed the long segment of thick-walled ascending colon and caecum; if perforation is suspected, ultrasound and CT might be preferable to a contrast enema.

Cecal Diseases↗
PubMed1986

Ventilatory effects of propofol during induction of anaesthesia. Comparison with thiopentone.

The ventilatory effects of induction of anaesthesia with either propofol 2.5 mg/kg or thiopentone 4.0 mg/kg have been observed in patients premedicated with either atropine alone or papaveretum and hyoscine. Induction of anaesthesia with propofol was accompanied by a greater degree of ventilatory depression which was of longer duration than following thiopentone. The effect was accentuated by the opioid premedication.

Adult↗
PubMed1986

Attitudes and normative beliefs as predictors of smoking intentions and behaviours: a test of three models.

This paper considers three potentially important modifications to the theory of reasoned action (Fishbein, 1980). It was hypothesized that behavioural norms, or beliefs about the behaviours of others, are important influences above and beyond subjective norms; the effects of attitudes and normative beliefs on intentions and behaviours are interdependent and interactive rather than additive; and the beliefs underlying subjective and behavioural norms are multidimensional rather than unidimensional. These hypotheses were tested in two surveys of smoking intentions and behaviour. The respondents in the first study were primary school children and those in the second study were college students. In both cases behavioural norms and the attitude-normative belief interactions led to significant increases in the prediction of smoking intentions and behaviour. Exploratory factor analyses also suggested that the beliefs underlying subjective norms may be multidimensional rather than unidimensional. These results thus support the hypotheses and suggest that the theory of reasoned action should be modified accordingly.

Adolescent↗