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Biomedical subjects

P Marsden

Publications and source records attributed to P Marsden.

At least 19 recordsLinked to original sources
PubMed2003

How do people with Type 2 diabetes perceive and respond to cardiovascular risk?

OBJECTIVES: To explore how people with Type 2 diabetes perceive cardiovascular risk, and how those perceptions might affect their motivation to make lifestyle changes. METHODS: The setting was a diabetes clinic in a UK teaching hospital. A qualitative study was conducted, using semistructured individual interviews and template analysis of content. The participants were 20 Type 2 diabetic patients, aged between 52 and 77 years, half with and half without cardiovascular disease (CVD). RESULTS: Whether they had CVD or not, most people were aware they were at risk of it, of its causative factors, and possible effects. However, they were more likely to attribute it to unchangeable factors like 'stress' and 'heredity', than medical risk factors like cholesterol and smoking. Patients with pre-existing CVD correctly regarded their risk as higher than those without. Few saw any direct link between being diabetic per se and cardiovascular risk. Lifestyle changes were precipitated by major life events and motivated by family support, fear of complications, and a belief that one should follow doctors' advice. A common reaction to CVD and diabetes was stoical acceptance, allowing patients to view their lives positively, whilst living with unpredictable potentially disabling diseases. CONCLUSIONS: Patients were unaware how strongly diabetes influences cardiovascular risk. Their ideas about risk were very different from those of conventional medicine, and provided individual rationales for making choices about treatment and risk-influencing behaviour. Contextual factors, such as family milieu, also influenced their behaviour. Clinicians should not assume patients share the same mental model of risk as they, and must be prepared to explore peoples' individual constructs and health beliefs.

Aged↗
PubMed2001

Amnesic syndrome and severe ataxia following the recreational use of 3,4-methylene-dioxymethamphetamine (MDMA, 'ecstasy') and other substances.

A 26-year-old woman suffered disseminated intravascular coagulation (DIC) and a brief respiratory arrest following recreational use of 3,4-methylene-dioxymethamphetamine (MDMA; 'ecstasy'), together with amyl nitrate, lysergic acid (LSD), cannabis and alcohol. She was left with residual cognitive and physical deficits, particularly severe anterograde memory disorder, mental slowness, severe ataxia and dysarthria. Follow-up investigations have shown that these have persisted, although there has been some improvement in verbal recognition memory and in social functioning. Magnetic resonance imaging and quantified positron emission tomography investigations have revealed: (i) severe cerebellar atrophy and hypometabolism accounting for the ataxia and dysarthria; (ii) thalamic, retrosplenial and left medial temporal hypometabolism to which the anterograde amnesia can be attributed; and (iii) some degree of fronto-temporal-parietal hypometabolism, possibly accounting for the cognitive slowness. The putative relationship of these abnormalities to the direct and indirect effects of MDMA toxicity, hypoxia and ischaemia is considered.

Adult↗
PubMed2000

"Spiritual starvation?": a case series concerning christianity and eating disorders.

METHOD: We describe the cases of four patients with eating disorders in whom complex interactions occurred among religious faith, pathogenesis of the eating disorder, and clinical management. RESULTS: In some of the cases, religious beliefs seemed to provide a containment of maladaptive behaviors, partly through prayer and through a sense of belonging to the religious community. In other cases, it proved difficult to separate the concept of a punitive God from the illness process. DISCUSSION: The cases are discussed with reference to a limited empirical literature. Similarities are noted between some religious institutions and eating disorder treatment regimes. This paper explores management issues, including the use of pastoral counseling and the ethics of addressing religious beliefs in therapy. We note the benefits of a rapprochement between psychiatry and religion.

Adult↗
PubMed2000

Erratum

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Journal Article↗
PubMed1998

Strategies to prevent thrombosis in xenotransplants.

Coagulation remains a major barrier to successful xenotransplantation. Identification of the role of complement activation in HAR and prevention of complement activation by high expression of DAF and CD59 has largely overcome HAR. Understanding the molecular basis of DXR and identification of novel strategies to prevent activation of endothelial cells using monoclonal antibodies, soluble inhibitors of coagulation, vaccination, antisense constructs, and recombinant DNA technology offers the promise of overcoming the thrombosis associated with xenotransplantation.

Acute Disease↗
PubMed1998

Regional differences in cerebral blood flow and glucose utilization in diabetic man: the effect of insulin.

To determine the effect of insulin on regional cerebral blood flow (rCBF) and glucose metabolism (CMRglu), we performed quantitative dynamic PET scanning of labeled water (H215O) and deoxyglucose (18FDG) using two protocols in 10 diabetic men. In protocol A, to test reproducibility of the technique, insulin was infused at 1.5 mU.kg-1.min-1 twice (n = 5). In protocol B, low (0.3 mU.kg-1.min-1) and high (3 mU.kg-1.min-1) dose insulin was given on separate occasions (n = 5). Euglycemia (5 mmol/L) was maintained by glucose infusion. In protocol A, CMRglu was 6% higher during the first infusion, and catecholamines were also increased, indicating stress. Blood flow was not different. Changing free insulin levels from 20.5 +/- 4.8 to 191 +/- 44.5 mU/L (P < 0.001, low versus high dose, protocol B) did not alter total or regional CMRglu (whole brain 36.6 +/- 4.0 versus 32.8 +/- 6.2 mumol.100 g-1.min-1, P = 0.32) or CBF (41.7 +/- 5.1 and 45.6 +/- 9.7 mL.100 g-1.min-1, P = 0.4) or rCBF. In cerebellum, CMRglu was lower than in cortex and the ratio between rate constants for glucose uptake and phosphorylation (K1 and k3) was reversed. There are regional differences in cerebral metabolic capacity that may explain why cerebral cortex is more sensitive to hypoglycemia than cerebellum. Brain glucose metabolism is not sensitive to insulin concentration within the physiologic range. This suggests that intracerebral insulin receptors have a different role from those in the periphery.

Adult↗
PubMed1998

Interictal regional slow activity in temporal lobe epilepsy correlates with lateral temporal hypometabolism as imaged with 18FDG PET: neurophysiological and metabolic implications.

OBJECTIVES: The phenomenon of interictal regional slow activity (IRSA) in temporal lobe epilepsy and its relation with cerebral glucose metabolism, clinical data, MRI, and histopathological findings was studied. METHODS: Interictal 18F-fluorodeoxyglucose positron emission tomography (FDG PET) was performed under continuous scalp EEG monitoring in 28 patients with temporal lobe epilepsy not associated with intracranial foreign tissue lesions, all of whom subsequently underwent resective surgery. Regions of interest (ROIs) were drawn according to a standard template. IRSA was considered lateralised when showing a 4:1 or greater ratio of predominance on one side. RESULTS: Sixteen patients (57%) had lateralised IRSA which was always ipsilateral to the resection and of maximal amplitude over the temporal areas. Its presence was significantly related to the presence of hypometabolism in the lateral temporal neocortex (p=0.0009). Logistic regression of the asymmetry indices for all measured cerebral regions confirmed a strong association between IRSA and decreased metabolism of the posterior lateral temporal neocortex only (p=0.009). No significant relation could be shown between slow activity and age at onset, duration of the epilepsy, seizure frequency, and MRI evidence for hippocampal atrophy. Furthermore, IRSA was not specifically related to mesial temporal sclerosis or any other pathology. CONCLUSIONS: Interictal regional slowing in patients with temporal lobe epilepsy not associated with a mass lesion is topographically related to the epileptogenic area and therefore has a reliable lateralising, and possibly localising, value. Its presence is irrelevant to the severity or chronicity of the epilepsy as well as to lateral deactivation secondary to neuronal loss in the mesial temporal structures. Although slow EEG activity is generally considered as a non-specific sign of functional disturbance, interictal regional slowing in temporal lobe epilepsy should be conceptualised as a distinct electrographic phenomenon which is directly related to the epileptogenic abnormality. The strong correlation between interictal regional slowing and lateral temporal hypometabolism suggests in turn that the second may delineate a field of reduced neuronal inhibition which can receive interictal and ictal propagation.

Adolescent↗
PubMed1996

Human interaction with technology: the accidental user.

Information technology is part of a growing number of applications in work and everyday life. It seems inevitable that the average person soon will have to interact with information technology in many ways, even when there is no desire to do so. Examples include finding a book in a library, personal financial transactions, the health sector, traffic and transportation, process control, etc. People who in this way are forced to interact with information technology shall be called accidental users. The accidental users poses a particular challenge to the design of technological artefacts because the disciplines of dealing with human-machine interaction are predicated on the assumption that users are motivated and have a minimum level of knowledge and skills. In particular, models of 'human error' and human reliability implicitly assume that users are benign and only fail as anticipated by designers. In this paper we investigate the extent to which current models of human erroneous actions and cognitive reliability can be used to account for interactions between accidental users and technology.

Attitude to Computers↗
PubMed1996

Cardiac function, metabolism and perfusion in Duchenne and Becker muscular dystrophy.

We studied 23 DMD and eight BMD patients using cardiac echo, 24 h ECG and positron emission tomography (PET) with the radiotracers N-13 ammonia and F-18 fluorine deoxyglucose. The ECG was abnormal in 23 cases with alterations in the PR and/or QT intervals, abnormal Q waves in the lateral leads and ST segment depression. Twenty-four hour ECG showed that patients were more likely to produce premature ventricular ectopic beats with advancing age and 17 patients had paroxysmal ST segment depression. LV function was normal or mildly reduced in 24 cardiac echoes. PET studies were visibly abnormal in 15 patients. Regional perfusion defects involving the apex, lateral or anterior left ventricular walls were present, nine cases demonstrated a corresponding increase in glucose metabolism. Three out of 15 demonstrated matched perfusion/metabolism defects. One BMD had severe LV dilation with globally poor perfusion and metabolism. The abnormalities seen with PET were confirmed with both quantitative and semi-quantitative analysis of radioactive counts. Similar results were obtained for both DMD and BMD, where both groups demonstrated significant regional perfusion/metabolism mismatches. We have shown a reduced uptake of N-13 ammonia which is indicative of a reduction in myocardial perfusion. The use of N-13 ammonia to measure perfusion has been validated in animal studies. PET with either N-13 ammonia- or oxygen labelled water can be used to measure myocardial perfusion. We chose N-13 ammonia as this was most readily available to us.

Adolescent↗
PubMed1995

Medical education.

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Clinical Competence↗
PubMed1994

Whole-body 18F-fluorodeoxyglucose positron emission tomography in preoperative evaluation of lung cancer.

Despite use of computed tomography, some lung cancer patients are found to have unresectable disease at surgery, or they present early with metastases. We studied whether whole-body positron emission tomography (PET) with 18F-fluorodeoxyglucose (18FDG) would improve the preoperative detection of metastases. We retrospectively analysed 34 patients with "operable" non-small-cell lung cancer who underwent 18FDG PET after routine assessment. Management changes produced by the PET scan and confirmatory tests were reviewed. PET identified unsuspected malignant lesions in 10 (29%) patients. Management changes occurred in 14 (41%), including 6 (18%) patients who were changed to non-surgical therapy. These data suggest that whole-body 18FDG PET improves preoperative assessment of lung cancer patients.

Aged↗
PubMed1994

Clinical and immunopathological aspects of disseminated cutaneous leishmaniasis.

The clinico-pathological and immunological findings in eight patients from Bahia, Brazil with disseminated cutaneous leishmaniasis are described. This condition differs from anergic diffuse cutaneous leishmaniasis (DCL) and from classical American cutaneous leishmaniasis (ACL). The number of lesions in these patients ranged from 75 to 800 and were characterized by papules and an acneiform type of lesion with a few ulcers rather than nodules that are the main characteristic of DCL. On the other hand the high incidence of mucosal disease (38%) in patients with disseminated cutaneous leishmaniasis make the prevalence of mucosal involvement in this condition higher than that observed in ACL. L. amazonensis (five cases) and L. braziliensis (two cases) were the causal agents in the patients where the infecting agent was characterized. Antibody titers in disseminated cutaneous leishmaniasis were higher than those observed in ACL and patients with the highest antibody titers had mucosal involvement. Abnormalities in cellular immunity that are not observed in ACL such as decrease in CD4+ cells and absence of T cell response to leishmania antigen were observed in several patients with disseminated cutaneous leishmaniasis but restoration of these abnormalities occurred after treatment. In spite of the great number of lesions, the therapeutic response was good in six patients with disappearance of the lesions in a period shorter than that observed in ACL. In the two patients that presented therapeutic failure the causal agent was L. amazonensis. In such patients there was a predominance of ulcerated lesions, and a high titer of antibody was detected.

Adult↗
PubMed1994

[The first 13 years of controlling Chagas' disease in Mambaí, Goiás, Brazil 1980-1992].

The Mambaí Project was launched in 1980 for the purpose of making a longitudinal clinical-epidemiologic study of Chagas' disease and of serving as a pilot program for the Ministry of Health of Brazil. At the beginning of the project, a census was carried out, the housing units were evaluated, and clinical examination and laboratory tests were performed on the population. After a phase of massive attack with insecticides, ongoing epidemiologic surveillance was instituted in order to detect residual foci of triatomine bugs in all the housing units in the municipality. The campaign included a program of health education combined with community participation. All infested housing units were selectively fumigated. In 1988 a new census was carried out, together with a serologic survey of children born after the control program was initiated. This article describes the results of epidemiologic surveillance during the first 13 years of the program. The prevalence of T. infestans in the housing units diminished to levels that suggest that vector transmission of the disease in Mambaí has been stopped. However, the risk of reinfestation from neighboring areas without control programs and the risk of colonization by secondary T. sordida vectors are factors that should be carefully monitored.

Animals↗
PubMed1992

Improved diabetes care in a UK health district.

The present study reports an analysis of diabetes care in general practice in a London Health District. A specialist nurse facilitator used various techniques to obtain practice information building up individual practice profiles. Four groups of constraints were identified as affecting the provision of GP diabetes care. Individual practice plans were formulated, working with key staff, to apply various interventions to ameliorate identified constraints. Using a non-prescriptive approach, GPs were encouraged to become involved in diabetes care in the way they felt most appropriate for their practice. Using this method, GP involvement in diabetes care has increased from 17 to 53% during the three years of the study.

Diabetes Mellitus↗
PubMed1991

Otolaryngology-head and neck surgery in the Canadian military: practice trends.

The practice of medicine in the Canadian military is poorly publicized except in times of war. The specialty of otolaryngology-head and neck surgery is not well known, even in medical circles. To correct this deplorable ignorance, a review was conducted on the otolaryngologic activities within the Canadian Forces. This revealed a dynamic specialty whose many contributions warrant acknowledgment. Starting with Major-General M.J.C.E. Fiset, who was the first such specialist in Canada, military otolaryngologists have maintained excellent standards of medical practice for the benefit of the Canadian soldier. This paper traces the development of military otolaryngology in Canada. Trends in the practice of this versatile specialty are presented.

Canada↗