PubMed Health⌕ Search

Biomedical subjects

S Kay

Publications and source records attributed to S Kay.

At least 19 recordsLinked to original sources
PubMed2006

Apical sparing in tako-tsubo cardiomyopathy.

BACKGROUND: Tako-tsubo cardiomyopathy (TTC) is an acute reversible cause of segmental myocardial dysfunction that is poorly understood. We have noted a variant of this condition where a tiny segment at the apex retains some contractile function. This paper delineates the frequency of this variant relative to the classical form and the clinical differences between patients suffering from the two forms. METHODS: All cases of TTC (n = 35) were identified from our infarct angiography database and separated on the basis of apical sparing (n = 14) or no apical sparing (n = 21). RESULTS: Compared with the classical form, those with apical sparing were significantly younger (63 +/- 12 vs 72 +/- 13 years) and were more likely premenopausal (5/14 vs 0/21) and had higher ejection fractions (35 +/- 6% vs 32 +/- 4%). There was a trend towards higher recurrence (4/21 vs 0/14). There were no differences in time or season of presentation, precipitant stressor, premorbid drug therapy, haemodynamics at catheterization or acute outcomes. CONCLUSION: The apical sparing variant of TTC is common, accounting for 40% of cases. While the patients are younger and more likely premenopausal, there are no other distinguishing features between the classical and the variant form.

Age Factors↗
PubMed2005

Usability: a critical success factor for managing change in the clinical info-structure.

There can be no doubt that the clinical info-structure is being significantly enriched with the deployment of new systems throughout the health sector. From a technological perspective, the initial emphasis has been mainly on functionality and only latterly on the usability of these clinical information systems. However, the large scale and rapid pace of the changes being wrought in the health sector will have a major impact on clinicians and patients, not least in how they interact with the technology. Therefore, it is not only hardware and software but people-ware, too, that needs to be actively managed; not simply a one-off functional specification but an ongoing, complex relationship. Usability is the human factor that encompasses the ethical, educational, and evaluative aspects of design. There is also a strong case for regarding usability of clinical information systems as a key critical success factor for the management of change within the health-care domain. In particular, the relationship between usability, and education and training is examined.

Information Systems↗
PubMed2005

Representing different views of acupuncture in a single ontology.

A major challenge for health informatics is to model the health-care domain knowledge into appropriate and useful ontologies. This is difficult, and modellers tend to simplify things dramatically by ignoring the fact that the health care domain encompasses a global perspective. The influx of complementary and alternative medicines from the East to the West, or indeed the ongoing colonialization of orthodox Western medicine into other non-western traditions requires multiple paradigms of delivering treatment to be considered simultaneously, side by side. Models and specifications need to be developed to encompass this richness and represent this complex reality so as to understand what the different concepts and terms in each tradition achieve. Acupuncture is used as a test case of cross-membership between two different paradigms. Here, we briefly outline requirements and answer possible objections to our approach before illustrating how we have modelled heterogeneous domain knowledge from different cultures, and across different paradigms, within a single ontology.

Acupuncture↗
PubMed2003

Patient reports as stories of clinical work: narrative and work in neuroradiology.

OBJECTIVE: This paper describes the connections between the radiology report and clinical work and considers the implications for computerisation. METHOD: A story representation is described that allows consideration of the radiology report as an active unit of narrative rather than a passive collection of data. This paper draws upon the results of a qualitative study of a neuroradiology department. RESULTS AND CONCLUSION: Radiology reports recount a patient condition but also represent and influence clinical work.

Anthropology, Cultural↗
PubMed2003

Early invasive revascularisation for patients critically ill after acute myocardial infarction: impact on outcome and ICU resource utilisation.

OBJECTIVE: To assess the value of early invasive revascularization for the initial management of critically ill patients after acute myocardial infarction in the daily practice of a University-affiliated referral hospital and to gauge the impact of such a strategy on the intensive care unit. PATIENTS AND METHODS: A prospective observational study on all patients admitted to the Royal North Shore hospital who had acute pulmonary oedema and/or shock prior to acute angiography for acute myocardial infarction from January 1(st), 1998 to December 31, 2001. RESULTS: During the study period 846 patients with acute myocardial infarction had coronary artery angiography, 139 had acute pulmonary oedema and/or shock prior to angiography. The average age was 70 years, 65% of whom were male. Approximately 70% of these patients were admitted to the intensive care unit and coronary artery bypass surgery was performed on 38%. Of those patients admitted to the intensive care unit, 95% required mechanical ventilation, 81% required inotropic support and 50% required intra-aortic Balloon counterpulsation. In-hospital mortality was 32%, 6 weeks mortality was 38% and 6 month mortality was 42%. CONCLUSIONS: Our results confirm the benefit of early invasive revascularisation for critically ill patients after acute myocardial infarction although a substantial amount of intensive care unit resources and cardiothoracic surgical expertise were required.

Journal Article↗
PubMed2002

Dendritic spine plasticity in hippocampus.

Most excitatory input in the hippocampus and cerebral cortex impinges on dendritic spines. Alterations in dendritic spine density or shape are suspected to be morphological manifestations of changes in physiology or behavior. The links between spine plasticity and physiological responses have probably been best studied in the hippocampus in the context of changes in the circulating levels of steroid hormones or long-term potentiation. Here we review and present data which indicate that both the age of the preparation and the timing of the analysis can dramatically effect the results obtained. Collectively the data suggest that different cellular and morphological strategies may be utilized at different ages and under different circumstances to effect similar physiological responses or behaviors.

Animals↗
PubMed2002

Association between past infection with Chlamydia pneumoniae and body mass index, low-density lipoprotein particle size and fasting insulin.

BACKGROUND: Chlamydia pneumoniae infection has been linked to the development of coronary heart disease (CHD), but its relationship to CHD risk factors is less clear. OBJECTIVE: To determine the relationship between past infection with C. pneumoniae and risk factors for CHD, including body weight amongst subjects with and without CHD. METHODS: Antibodies to C. pneumoniae and a range of CHD risk factors were determined in 170 subjects, of whom 43 had recent onset angina. Anthropometric, haemodynamic, lipid and metabolic measurements were obtained and related to antibody status in univariate and multivariate analyses. RESULTS: IgG seropositive (n = 62) did not differ from seronegative subjects in age but were significantly heavier (26.6 +/- 0.4 vs 25.5 +/- 0.3 kg/m2, P = 0.02). The prevalence of seropositivity was similar for subjects with and without CHD and for those with or without hypertension. Subjects with fasting insulin levels greater and those with LDL diameters below the median also had a significantly higher prevalence of seropositivity (45.3 vs 27.3%, P = 0.015 and 45.0 vs 29.4%, P = 0.045 respectively). However in multivariate analysis only body mass index remained significant (P < 0.05). Results were not explained by differences in socioeconomic class. CONCLUSION: Although the study has failed to find a greater prevalence of antibodies to C. pneumoniae amongst subjects with recent onset angina there were associations with a number of cardiovascular risk factors. An increase in body weight appears to underlie these relationships.

Aged↗
PubMed2001

Serotonergic lesion of median raphe nucleus alters nerve growth factor content and vulnerability of cholinergic septohippocampal neurons in rat.

About 45% of the serotonergic raphe neurons are reported to express nerve growth factor (NGF) receptors. We therefore investigated whether selective serotonergic lesions of the median or dorsal raphe nuclei are associated with changes in NGF protein levels of the brain and whether the loss of serotonergic function alters the vulnerability of cholinergic septohippocampal neurons. In adult rats the hippocampal NGF content changed in a biphasic way after lesion of the median raphe nucleus by 5,7-dihydroxytryptamine (5,7-DHT), with a significant increase after 2-3 weeks of up to 35%, followed by a significant reduction of 22% below control levels after 7 weeks, and a return to control levels within the following 4 weeks. By contrast, the decrease in hippocampal serotonin and 5-hydroxyindoleacetic acid remained throughout the observation period of 11 weeks, being still reduced to 15 and 30% of the control levels, respectively. In the frontal cortex the partial loss of the serotonergic innervation projecting from the median raphe was associated 5 weeks after 5,7-DHT injection with an increase in NGF protein of 39.7+/-9.6% (P<0.05), which remained elevated up to 11 weeks. At 9 weeks after 5,7-DHT, the lesion of the septohippocampal cholinergic neurons induced by the cholinotoxin ethylcholine aziridinium (AF64A) was exaggerated (P<0.05) as compared to AF64A-treated rats with intact serotonergic innervation. The present data indicate that a serotonergic lesion of the median raphe nucleus results in biphasic changes of NGF protein content and in a delayed increase in the vulnerability of septohippocampal cholinergic neurons.

5,7-Dihydroxytryptamine↗
PubMed2001

Surfactant levels after reversible tracheal occlusion and prenatal steroids in experimental diaphragmatic hernia.

BACKGROUND/PURPOSE: In normal lungs, fetal tracheal occlusion (TO) induces lung growth but decreases the number of type II cells; this is remedied if TO is released (TR) before delivery. In the current study, the effects of TO with or without TR on pulmonary structure and surfactant were assessed in the ovine model in which lung hypoplasia was induced by creation of a diaphragmatic hernia (CDH). METHODS: A left-sided CDH was created in fetal lambs at 80 days gestation; TO was done at 108 days; and TR at 129 days. All ewes were given 1 dose of glucocorticoids at 135 days. At 136 days, the fetus was delivered. Lung weight to body weight ratio, mean terminal bronchiole density, type II cell density, bronchoalveolar lavage fluid (BAL) phosphatidylcholine (PC), BAL surfactant protein A (SP-A) and B (SP-B), and lung tissue SP-A and SP-B were assessed in CDH, CDH with TO, CDH with TO and TR, and controls. RESULTS: CDH lungs were hypoplastic and structurally immature, but had increased type II cell density. TO with or without TR caused lung growth with normalization of lung parenchymal architecture and type II cell density. Although the BAL SP-A and BAL SP-B were similar in all 4 groups, the BAL PC was low in CDH with or without TO or TR. Also, lung tissue SP-B levels were low in CDH with or without TO or TR. However, lung tissue SP-A levels were normal in CDH, but low in CDH with TO with or without TR. CONCLUSIONS: Despite the finding that lung morphology was improved in CDH with TO with or without TR animals, surfactant content and composition remained abnormal. Although surfactant secreted early by the fetus into alveolar spaces contained normal levels of BAL SP-A and BAL SP-B, the low levels of BAL PC and low lung tissue stores of SP-B indicate that these experimental lambs may experience respiratory insufficiency soon after birth. This implies that prophylactic surfactant at birth might be beneficial for CDH.

Analysis of Variance↗
PubMed2001

Use of antenatal steroids to counteract the negative effects of tracheal occlusion in the fetal lamb model.

Tracheal occlusion (TO) in fetal lambs induces pulmonary hyperplasia but has negative effects on type II cells. The purpose of this study was to determine whether antenatal steroids could reverse the adverse effects of TO on lung maturation in fetal lambs. Sixteen time-dated pregnant ewes (term, 145 d) and 24 of their fetuses were divided into six groups: 1) TO at 117 d gestation; 2) TO at 117 d with a single maternal intramuscular injection of 0.5 mg/kg betamethasone 24 h before delivery; 3) TO at 117 d and release of the occlusion 2 d before delivery; 4) TO and release of the occlusion with maternal steroids; 5) unoperated controls without antenatal steroid treatment; and 6) unoperated controls, littermates of groups 1-4, treated with antenatal steroids. All fetuses were killed at 137 d gestation. Outcome measurements consisted of lung weight-to-body weight ratio; lung morphometry determined by mean terminal bronchial density; and assessment of type II pneumocytes by in situ hybridization to the mRNA of surfactant proteins B and C. Lung weight-to-body weight ratio and mean terminal bronchial density were significantly different among groups with TO and controls, indicating increased lung growth and structural maturation. The density of type II pneumocytes was markedly decreased by TO. Release 2 d before sacrifice significantly increased the density and surfactant activity of type II pneumocytes, but to levels still far from controls. Steroids alone had an effect similar to release. An additive effect was noted with steroids and 2-d release resulting in type II cell density comparable to controls. After fetal TO, a single maternal intramuscular dose of 0.5 mg/kg of betamethasone 24 h before delivery allows partial recuperation of the type II pneumocytes, an effect that is potentiated by 2-d release.

Animals↗
PubMed2001

Probabilistic risk assessment of cotton pyrethroids: III. A spatial analysis of the Mississippi, USA, cotton landscape.

Estimates of potential aquatic exposure concentrations arising from the use of pyrethroid insecticides on cotton produced using conventional procedures outlined by the U.S. Environmental Protection Agency's Office of Pesticide Programs Environmental Fate and Effects Division seem unrealistically high. Accordingly, the assumptions inherent in the pesticide exposure assessment modeling scenarios were examined using remote sensing of a significant Mississippi, USA, cotton-producing county. Image processing techniques and a geographic information system were used to investigate the number and size of the water bodies in the county and their proximity to cotton. Variables critical to aquatic exposure modeling were measured for approximately 600 static water bodies in the study area. Quantitative information on the relative spatial orientation of cotton and water, regional soil texture and slope, and the detailed nature of the composition of physical buffers between agricultural fields and water bodies was also obtained. Results showed that remote sensing and geographic information systems can be used cost effectively to characterize the agricultural landscape and provide verifiable data to refine conservative model assumptions. For example, 68% of all ponds in the region have no cotton within 360 m and 92% of the ponds have no cotton within 60 m. Only 2% of ponds have cotton present in all directions around the ponds and within 120 m. These are significant modifications to conventional pesticide risk assessment exposure modeling assumptions and exemplify the importance of using landscape-level risk assessments to better describe the Mississippi cotton agricultural landscape. Incorporating spatially characterized landscape information into pesticide aquatic exposure scenarios is likely to have greater impact on the model output than many other refinements.

Animals↗
PubMed2001

Ontological and epistemological views of 'headings' in clinical records.

This paper presents a theoretical framework for analyzing the structure and use of headings in clinical narrative. We are researching the proposed UK national standard of headings for communicating clinical information. We investigate three topics with respect to these headings) conformance to standards and systems) coverage and reliability) navigation and interpretation. The method described here is used to analyse the three distinct topics in a coherent and systematic way deploying a variant of functional analysis to consider the meaningfulness and interpretation of headings from both the clinician' and system' perspectives.

Humans↗
PubMed2001

Clinical narrative and clinical organisation: properties of radiology reports.

Radiology reports, as a form of clinical narrative, are more than a repository of patient information but are active in patient care. They are not unique and individual to each patient but have structured content suitable for supporting the activities of care. We consider these activities of care and how they manifest in the report. This recognition of the infusion of clinical organisation in clinical narrative leads to the recognition of seven properties of radiology reports: labels, concepts, genre, structure, author, subject, reader. These properties exist across two relationships: the intertextual relationship between radiology reports and the interpersonal relationship between a radiology report and people.

Humans↗
PubMed2001

Building coalitions.

Educating people on Medicare about their benefits and rights is a task often undertaken by multiple organizations in a given community. In some areas these groups have chosen to work together as a coalition in order to pool their capabilities and resources. In this brief, we explore the topic of coalition-building, focusing on specific "how-to's" and using real-life examples from the experiences of the Coalition to Monitor Medicare Managed Care (CMMMC) in Cleveland, OH.

Health Care Coalitions↗