In the USA, the incidence of kidney cancer has increased 43% since 1973. The risk of the disorder is higher in men than in women and increases with age. The von Hippel-Lindau tumour-suppressor gene is inactivated in over 75% of sporadic cases. Metastatic disease is present in 20-30% of patients at diagnosis. Early-stage kidney cancer is treated with a radical nephrectomy, but under certain circumstances a partial nephrectomy may be done. Tumour thrombus into the vena cava or right atrium requires thoracotomy and hypothermic circulatory arrest for successful removal of the tumour, but should not be done if extensive nodal or frank metastatic disease is present. Interleukin-2 is the systemic therapy of choice for metastatic disease at present, with long-term relapse-free survival of 5-8%. Several treatments including anti-angiogenesis drugs, cyclin-dependent kinase inhibitors, and differentiating agents are being actively investigated. Fluorouracil has a 10-15% response rate, and surgical excision of isolated metastases should always be considered. Therapy for metastatic renal cancer remains inadequate, but recent developments in basic and clinical research suggest future improvement.

Vertigo is a subtype of dizziness, which results from an imbalance within the vestibular system. This seminar focuses on three common presentations of vertigo: prolonged spontaneous vertigo, recurrent attacks of vertigo, and positional vertigo. The patient's history is usually the key to differentiation of peripheral and central causes of vertigo. The most common cause of vertigo, benign paroxysmal positional vertigo, can be cured with a simple positional manoeuvre. Other common causes of vertigo include vestibular neuritis, Ménière's syndrome, migraine, and vertebrobasilar insufficiency. Treatment should be directed at the underlying cause whenever possible, but antivertiginous and antiemetic drugs can suppress symptoms when a specific cause cannot be found. These drugs are generally not indicated for long-term daily use, however, since they may interfere with the normal compensation process.

Studies to assess the prognostic value of early neurological and neurophysiological findings in patients with anoxic-ischaemic coma have not led to precise, generally accepted, prognostic rules. We did a systematic review of the relevant literature to assess whether such rules could be derived from the combined results of these studies.

Cannabis is the most widely used illicit drug in many developed societies. Its health and psychological effects are not well understood and remain the subject of much debate, with opinions on its risks polarised along the lines of proponents' views on what its legal status should be. An unfortunate consequence of this polarisation of opinion has been the absence of any consensus on what health information the medical profession should give to patients who are users or potential users of cannabis. There is conflicting evidence about many of the effects of cannabis use, so we summarise the evidence on the most probable adverse health and psychological consequences of acute and chronic use. This uncertainty, however, should not prevent medical practitioners from advising patients about the most likely ill-effects of their cannabis use. Here we make some suggestions about the advice doctors can give to patients who use, or are contemplating the use, of this drug.

The treatment of acromegaly and hyperprolactinaemia has been improved by the availability of effective and well-tolerated slow-release somatostatin analogues and dopamine agonists with long-lasting activity, such as cabergoline. The use of these drugs has extended the possibility of treatment to patients who would have responded poorly to the previously available compounds, such as octreotide or bromocriptine, and to those who were intolerant to pharmacotherapy. Moreover, the improvement in the management of acromegaly has enabled the reversal, at least partly, of cardiomyopathy and sleep apnoea, two important risk factors for morbidity and mortality in these patients.

Compared with those in industrialised countries, people in developing countries have little access to treatment for HIV infection, or for many other diseases including cancer, tuberculosis, and malaria. Although attention has been paid to areas such as provision of essential drugs, strengthening of infrastructures and service delivery, human rights, and appropriate health technologies, great inequalities remain. The HIV epidemic has highlighted these differences, because technological advances and the response of people infected with HIV have enabled the sharing of experiences across regions and brought the contrast into focus.

Seasonal affective disorder (SAD) is a form of recurrent depressive or bipolar disorder, with episodes that vary in severity. Seasonal patterns of depressive episodes are common, but SAD seems to be less common than such patterns suggest. SAD was at first believed to be related to abnormal melatonin metabolism, but later findings did not support this hypothesis. Studies of brain serotonin function support the hypothesis of disturbed activity. The short-allele polymorphism for serotonin transporter is more common in patients with SAD than in healthy people. Atypical depressive symptoms commonly precede impaired functioning, and somatic symptoms are frequently the presenting complaint at visits to family physicians. The best treatment regimens include 2500 Ix of artificial light exposure in the morning. When patients seem to have no response or to prefer another treatment, antidepressants should be considered.

Imaging studies of early synovitis suggest that the first abnormality to appear in swollen joints associated with spondyloarthropathy is an enthesitis (inflammation at sites where ligaments, tendons, or joint capsules are attached to bone). We propose that the synovitis of spondyloarthropathy is secondary to liberation of proinflammatory mediators from the enthesis, whereas the synovitis of rheumatoid arthritis is primary. This suggestion allows a classification of arthritis as either primary synovial (rheumatoid-like) or entheseal (spondyloarthropathy-like) and allows differentiation of presentation of a polyarthritis with a good prognosis (spondyloarthropathy-like), from that with a bad prognosis (rheumatoid arthritis). Pathogenesis of spondyloarthropathy, in particular the part played by HLA-B27 and micro-organisms, should be assessed at the enthesis rather than in the synovium.