Sustainable energy, economic growth and public health

Dramatic economic growth over the last 50 years has been accompanied by widening inequalities world-wide in wealth and energy consumption, diminished life expectancy in some countries, and deteriorating indices of environmental sustainability including loss of bio-diversity. Raised output of carbon dioxide (CO2) and other greenhouse gases due to increased economic and industrial activity is causing progressive climate change, leading in turn to direct and indirect adverse effects on health. Emissions of greenhouse gases can be lowered by increased use of renewable energy sources, for example, wind power in the United Kingdom (UK), greater energy efficiency and other measures to promote sustainability. The experience of some developing countries shows that favourable indicators of health and development can accompany a low output of greenhouse gases. It is unclear whether contemporary political and social systems can deliver improved human development without increased use of fossil fuels and other resources.     

Long-term follow-up data from the Shunt Design Trial

Background: A previously reported multicenter randomized trial assessed whether 2 new shunt valve designs would reduce shunt failure rates compared to differential pressure valves. The study did not show a significant difference in the time to first shunt failure. Patients entered the trial between October 1, 1993, and October 31, 1995. The primary results were based on the patients' status as of October 31, 1996 (a minimum follow-up of 1 year). This report describes the late complications based on the patients' most recent follow-up. Methods: Three hundred and forty-four hydrocephalic children at 12 North American and European centers were randomized to 1 of 3 valves: a standard differential pressure valve; a Delta valve (PS Medical-Medtronic) or a Sigma valve (NMT Cordis). Patients were followed until their first shunt failure. Shunt failure was defined as shunt surgery for obstruction, overdrainage, loculation or infection. If the shunt did not fail, follow-up was continued until August 31, 1999. Results: One hundred and seventy-seven patients had shunt failure. Shunt obstruction occurred in 131, overdrainage in 13, loculated ventricles in 2 and infection in 29. The overall shunt survival was 62% at 1 year, 52% at 2 years, 46% at 3 years, 41% at 4 years. The survival curves for the 3 valves were similar to those from the original trial and did not show a survival advantage for any particular valve. Conclusions: Prolonged follow-up to date does not alter the primary conclusions of the trial: there does not appear to be one valve that is clearly the best for the initial treatment of pediatric hydrocephalus.     

Chemoprevention of spontaneous tumorigenesis in nullizygous p53- deficient mice by dehydroepiandrosterone and its analog 16alpha-fluoro- 5-androsten-17-one

Transgenic mice with both alleles of the p53 tumor suppressor gene product 'knocked out' by gene targeting are susceptible to early development of tumors, chiefly lymphomas and sarcomas. Compared with the control group, administration of dehydroepiandrosterone (DHEA) at 0.3% of the diet to male p53-deficient mice extended their lifespan by delaying death due to neoplasms (from 105 to 166 days on study, P = 0.002), primarily by suppressing lymphoblastic lymphoma (from 45 to 6% of neoplastic deaths, P = 0.010). Treatment with a synthetic DHEA analog, 16alpha-fluoro-5-androsten-17-one (compound 8354), at 0.15% of the diet also increased lifespan, to 140 days for mice that developed tumors (P = 0.037). The effects of these steroids on lifespan and tumor development did not appear to be strongly related to inhibition of food consumption and weight gain, in that a group pair-fed with control diet to the reduced food consumption of the DHEA-treated group developed and died of the same types of neoplasms at the same rate as the controls fed ad libitum. The chemopreventive effect of these steroids has been proposed to be due to suppression of DNA synthesis by inhibition of glucose 6-phosphate dehydrogenase, the rate-limiting enzyme of the pentose phosphate pathway. Although DHEA and its analog are strong non- competitive inhibitors of this enzyme in vitro, treatment with DHEA did not deplete cellular nucleotide pools in the liver, as would have been predicted. The chemopreventive effect of DHEA in this model may be due to steroid-induced thymic atrophy and suppression of T cell lymphoma, permitting these mice to survive long enough to develop tumors with longer latency.      

A BPA survey of recently appointed consultants

A postal survey of recently appointed consultant paediatricians was undertaken to determine whether they perceived their training had adequately equipped them for their current job. The response rate was 69% (207/299). After excluding replies from consultants trained outside the UK the analysis was carried out on 167 replies. Trainees held a mean 5.2 posts during general and higher professional training, necessitating a mean 1.8 house moves. Altogether 82% felt moves were beneficial to training but 46% found moves 'very disruptive' to family life. Only 12% of district general hospital and 22% of teaching hospital senior registrars took two research sessions a week. Supervision and training in research was absent or poor for more than 60%; 24% felt major changes and 55% moderate changes were needed to current training. Training in non-clinical skills was particularly in demand and a curriculum for both trainers and trainees with regular appraisals is required. Research at senior registrar level needs review and educational methods improved to achieve better training in a shorter period.     

Prevention of cardiovascular disease.

1. Major risk factors for coronary heart disease (CHD) are smoking, blood pressure and blood cholesterol and they interact in a multiplicative fashion. Family history of premature coronary heart disease and lack of exercise also contribute. Obesity increases risk probably mainly by its effect on blood cholesterol and blood pressure. Heavy alcohol consumption is a risk factor for stroke. 2. Prevention may be opportunistic or in specially organized clinics, the latter being less likely to result in the attendance of high risk individuals. 3. Worthwhile reductions in cigarette smoking can be achieved by brief advice and follow-up. Literature on smoking and other aspects of prevention is available from the district health education department. 4. Risk scores can be used to calculate the risk of coronary heart disease. They can help to indicate the advisability of measurement of blood cholesterol and to focus limited resources on those at highest risk by helping to define a ''special care group''. 5. Indications for measuring blood cholesterol are: a family history of premature coronary heart disease or hyperlipidaemia, personal history of coronary heart disease, clinical evidence of raised lipids (xanthelasma, corneal arcus under 50, xanthomas at any age), a high risk of coronary heart disease according to a risk score. Many would also include those under treatment for hypertension and diabetes. 6. Dietary advice can moderately reduce blood cholesterol. The proportion of calories from fat should be reduced from the current average of around 40% to a maximum of 33%. Dietary advice should be tailored to the patient''s current diet. An increase in vegetables and fruit can be generally advocated. 7. Regular exercise has a worthwhile role to play in prevention. Rapid walking, jogging and swimming may all be suitable, as may be heavy gardening and housework. 8. A small proportion of patients may require lipid-lowering drugs. These include resins (cholestyramine and colestipol), fibrates (eg bezafibrate and gemfibrozil) and more recently HMG CoA inhibitors (eg simvastatin). The HMG CoA inhibitors produce large falls in cholesterol and may become first line drugs in future. Because of the current controversy about the effect of lipid-lowering drugs on total mortality, many believe that they should be reserved for those at the highest risk, for example patients with familial hypercholesterolaemia or with pre-existing coronary heart disease and a high plasma cholesterol (> 7.8 mmol/L). 9. The special care group defined by the practice should be offered regular follow-up.(ABSTRACT TRUNCATED AT 400 WORDS)     

Dementia in old age.

1. About 10% of patients aged 75 and over are demented to an appreciable degree; the proportion may exceed 20% in those over 85. 2. Potentially reversible causes include pernicious anaemia, hypothyroidism, frontal meningioma, and normal pressure hydrocephalus. In many cases, however, treatment has little effect on cognitive function. 3. Around 50% are due to Alzheimer''s disease, 20% to multi-infarct dementia, and a further 15-20% have both conditions. 4. Recognition is facilitated by using a standard test of cognitive function (the Abbreviated Mental Test Score or the Mini Mental State Examination). 5. Dementia must be distinguished from delirium and depression. 6. Investigations by the general practitioner include full blood count and TSH. Urine should be tested, particularly if there is incontinence. Physical examination should exclude intercurrent disease and check for neurological deficits. 7. Sudden onset of confusion without obviously remediable cause and the need for respite care are indications for referral. Patients may also be referred for initial assessment. 8. An individually tailored care package should be designed for each patient. It should be clear who is taking responsibility for follow-up and monitoring. 9. Carers should be supported, encouraged to ventilate their feelings, put in contact with appropriate voluntary groups, advised on appropriate allowances, and offered respite care when needed.