Prevalence of Ischemia on Myocardial Perfusion Scintigraphy of Pre- and Postmenopausal Women

Background

In postmenopausal women, the presence of risk factors for coronary artery disease (CAD) increases. However, the difference in prevalence of ischemia between pre- and postmenopausal women with multiple risk factors for CAD has not been well established.

Objectives

To compare the prevalence of ischemia on Tc^99m-sestamibi myocardial perfusion scintigraphy (MPS) in pre-and postmenopausal women, and to evaluate whether menopause can be considered an independent risk predictor of ischemia in women with multiple risk factors for CAD.

Methods

This study retrospectively assessed 500 MPS of pre- and postmenopausal women with multiple risk factors for CAD. Statistical analysis was performed by using Fisher exact test and univariate and multivariate analysis, a p value ≤ 0.05 being considered significant.

Results

Postmenopausal women represented 55.9% of the sample; 83.3% were hypertensive; 28.9%, diabetic; 32.1%, smokers; 25%, obese; 61.2% had high cholesterol levels; and 34.3% had known CAD. Postmenopausal women were more often hypertensive, diabetic and dyslipidemic, and had lower functional capacity on exercise testing (p = < 0.005). The presence of ischemia on MPS did not significantly differ between the pre- and postmenopausal groups (p = 0.395). The only variable associated with ischemia on MPS was known CAD (p = 0.004).

Conclusion

The results suggest that, in women with multiple risk factors for CAD, menopause was not an independent predictor of ischemia on MPS. Those data support the idea that the investigation of ischemia via MPS in women with multiple risk factors for CAD should begin prior to menopause.     

A neural model of binocular integration and rivalry based on the coordination of action-potential timing in primary visual cortex

In normal vision, the inputs from the two eyes are integrated into a single percept. When dissimilar images are presented to the two eyes, however, they compete for perceptual dominance, so that one eye's view suppresses that of the other. Recent evidence suggests that this phenomenon, known as binocular rivalry, arises through competition between alternative stimulus interpretations in extrastriate cortex. Because eye-specific information appears to be lost at this stage, it remains unclear how the stimulus conditions that yield binocular rivalry are distinguished from those that produce stable single vision. Using a neural network that models the mammalian early visual system, I investigate here the hypothesis that congruent and conflicting stimuli are distinguished by their different effects on the relative timing of action potentials in primary visual cortex (V1), where monocular inputs are first combined. In the model, congruent stimulation of both eyes results in synchronization of discharges among binocular neurons in V1. By contrast, conflicting stimulation of the two eyes results in neuronal asynchrony in this area. This asynchrony then produces rivalrous response suppression at later stages in the visual pathway. Synchronization of firing in V1, however, prevents such competition, thereby ensuring non-rivalrous responses. These novel effects of spike timing on competition emerge naturally from the network dynamics. The results suggest that input-related differences in relative spike timing at an early stage of visual processing may play an important part in the phenomena both of binocular integration and rivalry; furthermore, they indicate that the temporal patterning of cortical activity may be a fundamental mechanism of selection among competing stimulus representations.      

Suicide in Northern Ireland: a comparison of two quinquennia (1982–1986 and 1987–1991)

This study compares government records of death by suicide, in Northern Ireland, during two quinquennia in the decade 1982–1991. Specifically these quinquennia are 1982–1986 l 1987–1991. During the latter quinquennium there was an increse m rate for males in most age groups, except the 45–54 and the over 65 years age groups. However, females had an increased rate in the 15–24 and 35–54 years age groups, but have a decreased rate in the other age groups. There has been a decrease in the rate of suicides by poisoning with solids and liquids for both sexes. However, male suicide rates by more violent methods have increased substantially during the latter quinquennium. Three cohorts of males, those in the 15–24, 25–34, and 55–64 age groups, have shown substantial increases during the latter quinquennium. Suggestions for psychiatric intervention strategies are made.     

Managing to care: the importance of using existing information to guide service provision for informal carers

All managerial deciions are taken on the basis of the information. It is important that managers use appropriate information to base their decisions upon about service provision to ensure erhcient use or resources. This basic premise serves as a framework for examining how quantitative and qualitative information can be of help to nurse managers in taking these decisions in the context of developing services for informal carers. The current emphasis on surveys as a means of assessing client need is questioned, and it is suggested that a wealth of evidence, relating to the experience of carers, already exists. Examples of accounts which express the needs of informal carers are presented and their utility, in terms of highlighting the carers' perspective, is discussed to reinforce the importance of utilizing this information. The paper concludes that nurse managers can use these sources as a basis for decision-making in the area of service provision and this may result in a more effective use of resources through a needs-based approach.     

Managing nurses and nursing: short courses as role development

This paper describes the development over a 3-year-period of short management courses for registered nurses offered as part of a professional development educational programme by Oxfordshire Health Authority (OHA) Clinical Education and Practice Team (OXCEPT). The courses were seen as role development for staff nurses, team leaders, sisters, charge nurses and senior sisters, and the content and length of courses were altered, extended and developed in response to evaluation of the courses by tutors and participants. The emphasis is on integrating participants' clinical, managerial and educational roles, as professional practitioners managing nurses and nursing.