We propose that the basal ganglia support a basic attentional mechanism operating to bind input to output in the executive forebrain. Such focused attention provides the automatic link between voluntary effort, sensory input, and the calling up and operation of a sequence of motor programmes or thoughts. The physiological basis for this attentional mechanism may lie in the tendency of distributed, but related, cortical activities to synchronise in the gamma (30 to 50 Hz) band, as occurs in the visual cortex. Coherent and synchronised elements are more effective when convergence occurs during successive stages of processing, and in this way may come together to give the one gestalt or action. We suggest that the basal ganglia have a major role in facilitating this aspect of neuronal processing in the forebrain, and that loss of this function contributes to parkinsonism and abulia.

There have been many randomised trials of adjuvant tamoxifen among women with early breast cancer, and an updated overview of their results is presented.

The success of fibrinolytic and other therapies has reduced the mortality of myocardial infarction. However, many survivors develop congestive heart failure. Medical treatment of this disorder has limited efficacy, and cardiac transplantation has limited availability. Contrary to previous teaching about ischaemic injury, roughly 40% of segments involved in myocardial infarction may subsequently recover, either spontaneously or after revascularisation. The persistence of such viable myocardium means that previous approaches to treatment of myocardial infarction must be reappraised. This review examines the pathogenesis of this response, the techniques that may be used to identify the salvageable tissue, and the clinical implications. Myocardial revascularisation may improve symptom status, exercise capacity, and prognosis in selected patients with viable myocardium.

WHO's activities at country level have earned the organisation both criticism and praise. The organisation's technical publications are esteemed as authoritative guidelines for disease control. Successful disease-control programmes and contributions to health research have heightened WHO's reputation. The organisation has also provided the focus for evolution of important ideas, such as primary health care and the relevance of equity and other ethical issues. But WHO has been criticised for not adapting rapidly and logically to changes in the health field. With increasing national capacity in the more advanced developing countries, and with the involvement of new participants in the health sphere, the organisation needs to reassess its role at country level. My recommendation is that WHO improves its analytical capacity so that its programmes take into consideration the health needs of the country, its national capacity, and the contributions from other external agencies.

Leptin (from the Greek leptos=thin) was identified only 3 years ago. It has attracted huge attention both scientifically, with more than 600 publications, and in the media, where this protein has been portrayed as the way to a cure for obesity. Indeed, leptin was first described as an adipocyte-derived signalling factor, which, after interaction with its receptors, induced a complex response including control of bodyweight and energy expenditure. Leptin seems in addition to its role in metabolic control to have important roles in reproduction and neuroendocrine signalling. Human obesity is a complex disorder, with many factors playing a part; the pathophysiology of leptin is not as simple as it seems to be in rodent models of obesity.