MinervaBMJ 2007; 335 doi: https://doi.org/10.1136/bmj.39412.563426.471 (Published 29 November 2007) Cite this as: BMJ 2007;335:1162
About 1.6 billion mobile phones are in use throughout the world. Along with concerns about exposure to the electromagnetic fields emitted by mobile phone networks are fears that hearing may be damaged by using mobile phones. Thirty young and healthy volunteers with normal hearing had their auditory brainstem responses recorded before and immediately after 10 minutes of genuine or sham exposure to the 900 MHz pulsed electromagnetic field emitted by a commercial mobile phone. The analysis showed no significant differences in the latency of auditory brainstem waves either before or after genuine or sham exposure (BMC Public Health 2007;7:325; doi: 10.1186/1471-2458-7-325).
Sociable animals, including humans, need to rapidly recognise friend or enemy within their own species. Now we have evidence that human babies learn how to do this very early in life, before they can talk (Nature 2007;450:557-9; doi: 10.1038/nature06288). Researchers tested babies aged 6-10 months and were amazed to find that they could distinguish between the helpful or hindering actions of an individual toward a third party. The team speculates that such early engagement in social evaluation may serve as a foundation for moral thought and action later in life.
Exogenous erythropoietin is popular among oncologists to treat the anaemia often induced by chemotherapy. But the use of erythropoiesis stimulating agents is causing some concern to cardiologists and also to the oncologists themselves, who have noticed that in some patients tumours have grown after such agents were used. “Oxygen breathing” may offer an alternative. Renal tissue can be stimulated to increase production of erythropoietin when the patient breathes oxygen at normal atmospheric pressures, which, according to Medical Hypotheses (2007;69:1200-4; doi: 10.1016/j.mehy.2007.03.015), may offer a convenient, cheaper, and safer alternative to erythropoiesis stimulating agents.
Is acute appendicitis being overdiagnosed? Yes, especially in women, say surgeons in the Annals of the Royal College of Surgeons of England (2007;89:766-9; doi: 10.1308/003588407X209266). Histological confirmation of appendicitis was established in just 52% of women who had their appendix taken out, compared with 81% in men. Among the normal looking appendixes taken from women, several showed fibro-obliterative changes, luminal inflammation, serositis, and faecoliths, and one even had pinworm. In women at least, say the authors, diagnostic laparoscopy should be performed before appendicectomy.
Patients given total parenteral nutrition are at high risk of bloodstream infections. Intravenous energy intake and glucose are thought to lead to hyperglycaemia, which in turn leads to bloodstream infection. To test this idea, researchers analysed 200 consecutive patients who were started on total parenteral nutrition during one year. Increased energy intake, but not hyperglycaemia, was confirmed as an independent risk factor for bloodstream infections. The authors say that even short periods of increased energy intake should be avoided (Critical Care 2007;11:R114; doi: 10.1186/cc6167).
We're familiar with hip and knee replacements, but what about shoulders? End stage arthritis of the shoulder causes great pain and disability, especially in older people, and shoulder arthroplasty offers the chance of considerable improvement in function and the ability to remain independent. In one unit, 14% of shoulder replacement operations were performed in people over 80 and resulted in minimal morbidity and rapid rehabilitation (Journal of Bone and Joint Surgery 2007;89-B:1466-9; doi: 10.1302/0301-620X.89B11.18850).
Three cities in France took part in a cohort study to find out if diet contributes to the risk of developing dementia (Neurology 2007;69:1921-30; doi: 10.1212/01.wnl.0000278116.37320.52). Daily consumption of fruit and vegetables was associated with a decreased risk of all causes of dementia, and a weekly consumption of fish was associated with a reduced risk of Alzheimer's disease, but only in people who were not carriers of the ε4 allele of ApoE. Regular consumption of omega-6 rich oils but not omega-3 rich oils or fish was associated with an increased risk of dementia among people who did not carry the allele.
Paroxysmal nocturnal haemoglobinuria puts patients at high risk of venous thrombosis, and once that happens, even when patients are given anticoagulants, the problem tends to progress and recur. Something better is needed—and a study in Blood (2007;110:4123-8; doi: 10.1182/blood-2007-06-095646) could have the answer. Eculizumab, an antibody to complement C5, seems to greatly inhibit thrombosis in affected patients. With treatment the thromboembolic event rate was 1.07 per 100 patient years, compared with 7.37 events per 100 patient years before eculizumab—a reduction of 85%.
Poorer countries need to identify cheap sources of dietary iron to tackle iron deficiency and anaemia. One possibility is seaweed, and a study in the Journal of Nutrition (2007;137:2691-5; http://jn.nutrition.org) analysed the bioavailability from four species of algae included in a rice based meal. The highest iron concentrations were found in Sargassum, with Gracilariopsis, Ulva, and Porphyra as runners-up. Cooking the algae didn't seem to affect the absorption of iron.