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Biomedical subjects

A Gale

Publications and source records attributed to A Gale.

At least 19 recordsLinked to original sources
PubMed2001

Hyoid bone position after surgical mandibular advancement.

A cephalometric evaluation of the changes in the horizontal and vertical placement of the hyoid bone and of those in the position of the head over the cervical spine after surgical mandibular advancement was undertaken. Seven linear and one angular measurement were investigated in 60 patients, 17 males and 43 females, before and one year after surgical mandibular advancement. The hyoid bone moved forwards horizontally in 78 per cent of the subjects, backwards in 17 per cent, and in 5 per cent of patients it retained its pre-operative position. It moved vertically downwards in 32 per cent of subjects, and in 63 per cent it moved upwards and closer to the body of mandible. The amount of horizontal and vertical change of the hyoid bone was associated with the corresponding change of the mandible after surgery. The vertical change was more distinct in females compared with males. There was variation in the position of the head over the cervical spine; it showed extension in 26.7 per cent of the sample, flexion in 71.7 per cent, and remained the same in only 1.6 per cent after surgery. The results show that with surgical mandibular advancement the hyoid bone follows mainly the advancement of the mandible and moves closer to the body of the mandible. However, there are variations in the changes of hyoid bone and head position that are difficult to predict.

Adult↗
PubMed1999

Developing the role of the generic healthcare support worker: phase 1 of an action research study.

This paper reports on the first phase of an action research practice development project to explore, develop and evaluate the role of the generic healthcare support worker in a high dependency rehabilitation service. The project is being jointly conducted by staff from the University of Southampton, the University of Portsmouth and the Isle of Wight Healthcare NHS Trust and phase 1 is supported by a grant from the NHS Executive (South and West). The aim of phase 1 of the project is to explore the attitudes of staff towards the implementation of the role of the generic healthcare support worker, particularly regarding the practical, professional and ethico-legal problems of the role. Professional and support staff from different parts of the service were interviewed in groups and the interviews were tape recorded, transcribed and subjected to a simple thematic analysis. Four themes emerged from the data relating to the challenge to professional boundaries, being a generic worker, outcomes for service and patients and implementing the role. As an action research project, the aim was not to produce findings that are generalizable beyond the practice areas in which they were generated, but it is nevertheless hoped that the reader might be able to apply some of the conclusions to his or her own setting.

Attitude of Health Personnel↗
PubMed1997

Electrophysiological measures of cognition in biological psychiatry: some cautionary notes.

Research into the electrophysiological correlates of mental illness is currently expanding, largely because of the availability of relatively inexpensive and powerful computers. However, improvements in technology do not always lead to enhanced methodological procedures; thus, there are concerns over the proper interpretation of the results of these investigations. Our argument is that electroencephalographic (EEG) research into psychopathology of psychiatric diseases should adopt a cognitivist model of mental dysfunction rather than a neurologist model of brain disease. Cognitive science has significant potential as an integrative framework for theorizing and researching psychiatric disorders and their treatment. Models of human cognitive functioning have rather special and unique features; these will make their impact upon the nature of both the analysis and interpretation of EEG data. The adoption of a sound model of brain function has implications for the methods to be used at different successive stages of the research process. We address a number of methodological requirements pertaining to: the recording and analysis of EEG signals, the laboratory context, the nature of the tasks, and the attribution of obtained effects. However, there are grounds for great caution. Even if the mapping of electrical changes in brain activity leads to a good approximation of the temporal and spatial dynamics of higher brain function, exploitation of such information presupposes a deeper understanding of both human cognition and the physiological basis of the EEG than is often displayed in the literature. To demonstrate this fundamental point, we draw a number of comparisons between traditional neurological approaches to brain assessment and contemporary cognitive psychophysiology.

Cognition↗
PubMed1995

A psychophysiological inquiry into the nature of the Sokolovian orienting response comparator model: skin conductance and EEG data.

The mechanisms which trigger the orienting response (OR) are still the subject of lively debate. Sokolov (1990) proposes the development of a multidimensional model of the physical parameters of stimulation. Recent OR research has shown that the skin conductance OR (SCOR) is related to task demands and controlled processing, although this is not so clear for central physiological indexes of orienting. Seventy-three subjects performed visual discriminations of stimuli within a warning-stimulus paradigm. The physical complexity of stimuli and their task relevance were manipulated within subjects, while the nonspecific effects of workload were controlled with a group factor. SCORs were measured concurrently with 1-s epochs of EEG alpha and theta power from Fz, Cz, Pz, and Oz. Neither index was reliably affected by the physical complexity of stimulation alone. However, both higher task relevance and higher workload significantly increased the magnitude of EEGORs and SCORs. Task averages of central and autonomic activity showed an overall pattern of covariation, but a second-by-second breakdown of EEG spectra suggests that the SCOR may be an aggregate of the activation of diverse brain mechanisms responsible for physiological orienting. The results are consistent with a model of orienting as a continuous dimension of resource allocation to anticipated and current task demands, rather than with the abrupt dichotomy between voluntary and involuntary orienting. Implications for the classical OR Sokolovian model are discussed.

Analysis of Variance↗
PubMed1993

U937 cells can utilize plasminogen activator to regulate human interferon-gamma.

Urokinase-type plasminogen activator (uPA) converts the proenzyme plasminogen to plasmin and thereby contributes to processes like cell migration, tissue remodeling, and cytokine processing. We report here that uPA produced by the human U937 promonocytic cell line also initiated the inactivation of recombinant interferon-gamma (rIFN-gamma) by plasmin-mediated proteolysis. When cultured serum-free with plasminogen, U937 promonocytic cells generated measurable levels of plasmin activity and destroyed the antiviral activity of exogenously added rIFN-gamma. This effect was not seen in the absence of plasminogen, was prevented by inhibitors of uPA and plasmin, and was accompanied by changes in the electrophoretic mobility of rIFN-gamma on polyacrylamide gels, consistent with limited proteolysis of the lymphokine. Culturing U937 cells or blood monocytes for 48 h led to an elevated expression of their surface uPA and an increase in their capacity to produce plasmin and inactivate rIFN-gamma. The ability of rIFN-gamma to induce Fc receptors on U937 cells could also be prevented by providing the cells with a source of exogenous plasminogen, indicating that U937 cells could control their own activation in vitro through the action of uPA. The results of these studies support the conclusion that mononuclear phagocytes have the capacity to use uPA to regulate cytokine activity in vitro.

Fibrinolysin↗
PubMed1992

Motor nerve biopsy in severe Guillain-Barré syndrome.

We undertook a biopsy of a terminal branch of the musculocutaneous nerve in a man with severe Guillain-Barré syndrome and very small distally evoked action potentials. The biopsy showed pronounced subperineurial edema, macrophage infiltration, and many axons that had been completely demyelinated, some associated with intratubal macrophages. The biopsy unequivocally identified the pathological process as primary demyelination, not axonal degeneration, and was more informative than previous reports of sural nerve biopsies in patients with Guillain-Barré syndrome.

Axons↗
PubMed1990

Proteolytic inactivation of cytokines by Pseudomonas aeruginosa.

Pseudomonas aeruginosa alkaline protease and elastase are thought to contribute to bacterial invasiveness, tissue damage, and immune suppression in animals and patients infected with the bacterium. This study examined the ability of the two proteases to inactivate a number of cytokines that mediate immune and inflammatory responses. Human recombinant gamma interferon (rIFN-gamma) and human recombinant tumor necrosis factor alpha were inactivated by both proteases. Murine rIFN-gamma was relatively resistant to alkaline protease but was inactivated by elastase, and human recombinant interleukin-1 alpha and recombinant interleukin-1 beta were resistant to the effects of both proteases. Western immunoblots suggested that cytokine inactivation by these proteases, where it occurred, required only limited proteolysis of the polypeptides. The ability of different P. aeruginosa strains to inactivate IFN-gamma appeared to require the production of both proteases for optimum activity. These results indicate that in vitro cytokine inactivation by Pseudomonas proteases is selective, requires only limited proteolysis, and in certain instances reflects the cooperative effects of both proteases.

Animals↗
PubMed1988

Relationship of lateral eye movements recorded in the dark to verbal and spatial question types.

Lateral eye movements (LEMs) were recorded in normal subjects to verbal and spatial questions in the dark using infra-red recording techniques to assess whether clearer LEM-question type relationships are observed when the potentially confounding effects of visual stimulation are absent. Verbal questions elicited more rightward LEMs than spatial questions. However, spatial questions were not associated with leftward LEMs. It is argued that while infra-red recording techniques may be optimal for recording LEMs to verbal questions, the above results question the generalizability of strong LEM-spatial relationships obtained for a single blind subject by GRIFFITHS and WOODMAN [Neuropsychologia 23, 257-262, 1985].

Adolescent↗
PubMed1988

Smoking patterns during cognitive performance.

Studies on the effects of smoking and performance in learning and memory tasks have followed one of two strategies: (a) either subjects are required to smoke at fixed intervals and/or rates, or (b) subjects are permitted to smoke freely in the absence of any monitoring or observation of smoking acts. The present studies allowed free smoking within a structured context, while exposed to intelligence test items for 30 seconds. Subjects were observed to vary their smoking acts (puffing, tapping) as a function of the temporal characteristics of the task. Subjects followed the same pattern across two independent studies. Such findings have clear implications for smoking studies since they indicate that how and why subjects smoke may (a) vary with context, and (b) affect different task inputs.

Adult↗
PubMed1985

Evidence of more rapid stimulus evaluation following cigarette smoking.

Experienced male smokers (greater than 15 cigarettes daily) performed a rapid visual information processing (RVIP) task requiring the detection of sequences of three consecutive odd or even digits in a series presented singly on a TV screen, at a rate of 100 digits/minute. Approximately 80 targets occurred every 10 minutes. All subjects took part in three test sessions: (a) Baseline of 10 minutes on the RVIP task, (2) treatment phase of 10 minutes smoking one cigarette (0.9mg or 1.5mg standard machine delivery of nicotine) or not smoking (NS), (3) posttreatment phase of 20 minutes on the task. Before these morning sessions subjects abstained from smoking for at least 12 hours. Smoking increased the number of correct detections and decreased response time compared with pre-smoking baseline and NS sessions. Analysis of vertex Event-Related Potentials to correct detections revealed a significant reduction in P300 latency following smoking compared to NS sessions. It is suggested that smoking has speeded up stimulus evaluation processes in these individuals. These data are consistent with the common self-report by smokers that smoking aids concentration.

Adult↗