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Biomedical subjects

G Davies

Publications and source records attributed to G Davies.

At least 217 records · Page 12Linked to original sources
PubMed1990

Drawing on memory: exploring the expertise of a police artist.

The use by the police of artists to draw likenesses of suspects is on the increase, yet there are few studies of their professional prowess. In the current study, art students observed one of six target faces before either drawing a likeness of the person themselves or collaborating with an experienced police artist. The likenesses produced by the police artist were judged as consistently superior to those made by the students, despite the artist working indirectly from the witnesses' verbal directions. Instructions to judge the target face in terms of likely character and personality led to better drawings than instruction to examine physical features when students worked with the artist but not when they drew on their own. These findings are discussed in terms of police practice and face processing theory.

Crime↗
PubMed1990

Managing organizational change: strategies for the female health care supervisor.

In responding to resistance to change in the current health care organization, the new female supervisor can learn to support her staff in encountering and accepting these changes. The strategies and skills discussed above are characteristic of a supervisory style that may naturally occur for women, but also can be incorporated into the leadership style of men in health care management today. Health care leaders of tomorrow must work from an androgynous framework in which the behavior patterns and responses of each gender are learned and used appropriately by both men and women. Sargent suggests that the best managers are androgynous and that this is the inevitable wave of the future. Whether man or woman, a supervisor should learn, accept, and use methods that are characteristic of both sexes to be successful in managing people. Women and men must learn from each other's strengths and share these diverse skills. Given that women now outnumber men in health care management positions and organizations are changing to a more nurturing environment, the androgynous supervisor will be the successful leader of the future. Finally, women in health care supervisory positions have the potential to bring change where it is badly needed. Women in these roles often have a system wide view of health care policy issues that recognizes less federal commitment to social programs. Many women in health care positions believe that the issues of children, women, the elderly, the poor, and the homeless need focused attention. The growing number of women in health care supervisory and leadership roles is an important factor in changing national health policy for the benefit of these groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Communication↗
PubMed1989

Normal extracellular calcium levels block kindled seizures.

Seizures induced in animals by the kindling procedure have been described as an effective model of human epilepsy, principally because of the long lasting nature of this phenomenon (J. O. McNamara, 1984, Ann. Neurol. 16: 572-576). Permanent changes in the central nervous system associated with kindling should therefore provide insight onto of some forms of naturally occurring epilepsy. We report here the observation that in rats with fully developed kindled seizures, the exposure of the stimulation site to artificial cerebral spinal fluid (CSF) containing normal levels of calcium is able to block completely the seizure event. Exposure of the stimulation site to artificial CSF without calcium resulted in the return of the complete seizure. This implies that extracellular calcium levels are chronically reduced at the stimulation site of kindled rats and that this change in ion levels is necessary for the expression of the seizure.

Animals↗
PubMed1989

Chronic spinal arachnoiditis following intracranial subarachnoid haemorrhage.

A 54-year-old woman presented with progressive gait imbalance and increased urinary frequency, associated with spinal arachnoiditis. The symptoms started after the occurrence of communicating hydrocephalus as a sequel of subarachnoid haemorrhage (SAH), and were initially attributed to post-SAH vasospasm, decompensating hydrocephalus and/or periventricular leuko-encephalopathy. Further clinical deterioration led to the diagnosis of thoracic spinal arachnoiditis, as a second complication of SAH.

Arachnoiditis↗
PubMed1989

The in-hospital development of cardiogenic shock after myocardial infarction: incidence, predictors of occurrence, outcome and prognostic factors. The MILIS Study Group.

The incidence, outcome and predictors of the in-hospital development of cardiogenic shock and its prognostic significance were analyzed in 845 patients presenting with acute myocardial infarction. Cardiogenic shock developed after hospitalization in 60 patients (7.1%). In half of these patients, cardiogenic shock developed at least 24 h after hospital admission. The in-hospital mortality rate was greater than 15 times higher for patients with cardiogenic shock than for patients without shock (65.0% versus 4.3%, respectively, p less than 0.001). Enzymatic evidence of infarct extension occurred in 23.3% of the patients with shock compared with 7.4% of those without shock (p less than 0.0001). Multivariate analysis indicated that independent predictors for the in-hospital development of cardiogenic shock were age greater than 65 years (p = 0.007), left ventricular ejection fraction on hospital admission less than 35% (p = 0.007), large infarct as estimated from serial enzyme determinations (that is, peak creatine kinase-MB isoenzyme greater than 160 IU/liter (p = 0.008), history of diabetes mellitus (p = 0.011) and previous myocardial infarction (p = 0.012). Patients with three, four or five of these risk factors had a 17.9%, 33.7% or 54.4% probability, respectively, of developing cardiogenic shock after hospital admission. Left ventricular function, as reflected by left ventricular ejection fraction (p = 0.04) and severity of left ventricular wall motion abnormality (p = 0.04), was the most important determinant of in-hospital mortality in the patients with cardiogenic shock.

Age Factors↗
PubMed1989

Coronary vasomotor tone: a heterogeneous entity.

Changes in coronary vasomotor tone are undoubtedly involved in the pathogenesis of many ischaemic coronary syndromes. The term coronary artery 'spasm' should be limited to the situations characterized by focal coronary constriction sufficient to cause transient total or sub-total coronary occlusion. Mild coronary artery constriction is also observed in many other situations, without even causing coronary artery occlusion. We present suggestive evidence that the mechanisms underlying coronary artery 'spasm' and 'physiological' coronary artery constriction are different.

Angina Pectoris, Variant↗
PubMed1989

Swine model of early adult respiratory distress syndrome induced by intravenous ethchlorvynol.

Although ethchlorvynol (ECV) has been used to induce pulmonary damage in animals, changes after injection of this drug have not been studied, nor has the stability of the animal been assessed after injection. Continuously monitored hemodynamic and respiratory changes were followed during and after iv injection of 55 mg/kg ECV in ethanol into anesthetized, paralyzed, and ventilated swine (n = 5) and compared to changes in a control group given ethanol alone (n = 5). Arterial and mixed venous saturations were measured by fiberoptic vascular catheters and oxygen exchange by a gas monitor. Twelve direct and derived variables were monitored every 20 sec using a computer data acquisition system. Arterial oxygen saturation was kept at 90 +/- 2% by adjustment of FIO2. Ethanol produced only transitory changes during infusion. Significant elevations in pulmonary vascular resistance (PVR), shunt (Qsp/Qt) and deadspace (VD/VT) were observed during and after ECV. These were unaccompanied by changes in cardiac output or arterial pressure. PVR increased by 137%, Qsp/Qt by 67%, and VD/VT by 28% over 30 min. These changes were then sustained in the postinfusion period, producing a stable model of early adult respiratory distress syndrome for 3.5 h.

Animals↗
PubMed1989

Close encounters of the witness kind: children's memory for a simulated health inspection.

A total of 128 children from each of two age groups (6-7 years and 10-11 years) took part individually in a simulated health check procedure. This involved direct confrontation between the child and an adult stranger in which the child was touched and an article of clothing (shoes) removed. One week later children took part in a series of tests which examined their testimony of the events in which they participated. Older children were superior to younger on both free and prompted recall of event and appearance information and made fewer errors, both relatively and absolutely, on recall of appearance but not events. The two age groups did not differ in their competence in the construction of Photofit pictures and showed no difference in performance on identification from a photographic array, irrespective of whether the adult was present or absent. The implications of these findings for the current debate over the legal admissibility of children's evidence are discussed.

Child↗
PubMed1988

Coronary constriction in acute myocardial infarction: role of nitrates.

We have investigated the coronary vasodilator responses to nitrates in the early stages of acute myocardial infarction before, during and after the administration of thrombolytic therapy. Before thrombolysis, intracoronary doses (2-4 mg) of isosorbide dinitrate failed to induce recanalisation of the totally occluded infarct related artery. Episodes of coronary reopening and reocclusion associated with ST-segment resolution and re-elevation were frequently observed both spontaneously before and during thrombolytic therapy. In 50-86% of patients, intracoronary isosorbide dinitrate promptly re-established full coronary patency immediately after acute reocclusion or whenever coronary occlusion was incomplete, both before and during thrombolysis. After thrombolysis further intracoronary isosorbide dinitrate dilated the infarct related stenoses but not uninvolved adjacent normal coronary branches. Coronary thrombosis and constriction frequently interact during the early phases of acute myocardial infarction. The combination of high local concentrations of nitrates with thrombolytic agents promotes stable coronary recanalization and may be beneficial in patients with acute myocardial infarction.

Coronary Vessels↗
PubMed1988

Adenosine-induced chest pain in patients with silent and painful myocardial ischaemia: another clue to the importance of generalized defective perception of painful stimuli as a cause of silent ischaemia.

Adenosine is formed from adenosine triphosphate within the ischaemic cells from where it is released into the coronary circulation. Adenosine exhibits several cardiovascular effects which tend to protect the ischaemic myocardium. Based on the observation that in healthy volunteers the intravenous infusion of adenosine produces angina-like chest pain, it has been recently proposed that another cardioprotective action of this substance could be provocation of angina. If this is the case adenosine should not produce chest pain in patients with silent ischaemia. To test this hypothesis we infused this substance intravenously at increasing doses of 50, 100, 150, 200, 250 and 300 micrograms kg-1 min-1 in eight patients with silent ischaemia (group A). All of them developed ST depression (1.8 +/- 0.2 mm) during exercise testing and seven also during adenosine infusion (1.1 +/- 0.8 mm). However, none of the patients had chest pain during exercise while seven had chest pain during adenosine. We then infused adenosine in eight other patients (Group B) who had painful ischaemia and an exercise tolerance similar to that of Group A patients (time to 1 mm ST depression 8.6 +/- 2.7 min and 8.4 +/- 3 min, respectively, P = NS). Adenosine induced chest pain in all Group B patients. The time to pain onset during adenosine was similar in the two groups (9.3 +/- 2.3 min in Group B and 12.4 +/- 4.9 min in Group A).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1988

Pre-existing coronary stenoses in patients with first myocardial infarction are not necessarily severe.

The sudden, often unheralded, onset of symptoms in acute myocardial infarction suggests that pre-existing coronary stenoses susceptible to acute thrombosis in the infarct-related artery may not necessarily have been severe. We investigated the severity of residual coronary stenoses after successful thrombolytic recanalization and the relationship to previous symptoms, collateral vessels and the extent of coronary artery disease in 60 consecutive patients at the time of presentation of their first acute myocardial infarction by performing quantitative coronary arteriography before, during and after intracoronary thrombolytic therapy. Recanalization was achieved in 48 (80%) patients with a residual stenosis of 58.1 +/- 10.8% (mean +/- ISD; range 33-82%) obstruction diameter and a minimum lumen calibre of 1.10 +/- 0.3 mm (range 0.39-1.95 mm). A residual stenosis of less than 60% obstruction diameter was present in 28 (47%) patients. When residual stenoses were mild, no acute collateral filling of the occluded artery was observed. After thrombolysis, residual infarct-related coronary stenoses in patients with their first acute myocardial infarction are not necessarily severely obstructive. This raises the problem of identifying which non-obstructive coronary stenoses are likely to occlude suddenly and why they do so.

Adult↗
PubMed1988

Reinstatement of context following exposure to post-event information.

In an earlier study, Jenkins & Davies (1985) reported significant interference to facial memory from exposure to an erroneous composite picture of a target in the interval between observation and test. Subjects (n = 194) in the present experiment first viewed a videotaped incident depicting a male target and then received a composite of the target which was designed to present either correct or misleading information concerning his appearance. Control subjects received no composite of the target. Following a delay of one week, all subjects were required to recall the appearance of the target in a cued recall questionnaire and to recognize him from a photospread. For half of the subjects, the context of the original incident was revived by means of a guided memory interview, modelled on Malpass & Devine (1981). The remaining subjects received no contextual reinstatement but simply completed recall and recognition tests. For subjects receiving no contextual reinstatement, interference in facial memory from the composites was observed both for recall and recognition of the target. However, for subjects in the context both for recall and recognition of the target. However, for subjects in the context condition, significant reductions in the influence of the misleading composites were observed. The theoretical and practical implications of these findings are discussed.

Adolescent↗