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     Dylan was prevented from giving one of the great unwritten speeches. He might have put some flesh on his amorphous left-wing views and articulated his true attitude to the new National Health Service, the pearl of the new Labour government, when he baulked, perhaps alarmed, as often in the past, at having to make a public statement. His politics in this period did creep out, however. A couple of years later he had earned three guineas for his apothegm credited in the insults column of Strand magazine. "One should tolerate the Labour government because running down Labour eventually brings you along side the Conservatives, which is the last place you want to be." ( Lycett, Andrew. Dylan Thomas. A New Life. London: Weidenfeld and Nicholson, 2003:273–4)

    Scientists have now learned that chronic pain, often leading to anxiety and depression, can also promote permanent neurological changes. It can shrink the brain and impair one of the most valuable mental functions: the ability to make good decisions. Scientists at Northwestern University have demonstrated that the overall volume of regional grey matter density in patients who have chronic back pain is considerably less than those of non-sufferers. Since the prefrontal cortex is crucial for emotional decision making the investigators studied decision making following this prefrontal atrophy and demonstrated significant defects in those patients with chronic pain. ( Scientific American 2004;290:22–3)

    Amniotic membrane, the innermost layer of the placental membrane, has been used as a surgical material in a variety of fields. In ophthalmic surgery the tissue has been used as a conjunctival graft. Recent reports have encouraged the use of preserved human amniotic membrane for ocular surface reconstruction in patients with severe ocular surface disease. Investigators from Japan have now studied sterilised freeze dried amniotic membrane. In this study, the tissue was characterised for its physical, biological, and morphological properties by stress tests, immunohistochemistry, electron microscopy, and cell culture. The preliminary reports of this study suggest that sterilised freeze dried amniotic membrane retained most of the physical, biological, and morphological characteristics of cryopreserved amniotic membrane and is therefore a useful biomaterial for ocular surface reconstruction. ( Investigative Ophthalmology and Visual Science 2004;45:93–9)

    Surfaces of the human malaria parasite are under intense immune pressure and their loci are subject to positive selection. Investigators in Japan have recently studied malaria antigen genes in isolated populations, especially in Vanuatu. These results indicate that a rapid evolution of repeat length polymorphism and stable single nucleotide polymorphisms occur in Plasmodium falciparum. The presence of these stable single nucleotide polymorphisms implies that malaria vaccine would be more effective where there is a limited gene pool, as in isolated populations. ( Science 2004;303:493)

    Approximately 25% of patients with visual hallucinations secondary to eye disease report hallucinations of text. The hallucinated text conveys little if any meaning, typically consisting of individual letters, words or nonsense letter strings. Researchers in London have described a patient with textual visual hallucinations consisting of grammatically correct meaningfully written sentences or phrases, often in the second person. The investigators suggest that syntacto-semantic visual hallucinations may represent a separate category of textual hallucinations related to the cortical network implicated in the auditory hallucinations of schizophrenia. ( Journal of Neurology, Neurosurgery and Psychiatry 2004;75:80–6)

    Cataract remains a major cause of blindness in the undeveloped world where there are simply not enough qualified staff to perform cataract procedures. A medical approach is clearly needed to slow or prevent cataracts. A strong body of biochemical animal and human evidence suggests that oxidative changes to lens proteins cause lenses to become opaque. Moreover, a protective effect of vitamins C and E in in vivo and in vitro animal studies has been demonstrated. In a study from Melbourne, Australia, however, a vitamin supplement to prevent cataract had a disappointing outcome. In this prospective, randomised, double masked, placebo, controlled clinical trial, vitamin E given for 4 years at a dose of 500 IU daily did not reduce the incidence of or progression of nuclear, cortical, or posterior subcapsular cataracts. This study does not support the use of vitamin E to prevent the development or slow the progression of age related cataracts. ( Ophthalmology 2004;111:75–84)

    Despite the well established evidence concerning cigarette smoking and lung cancer the industry continues to try to entice would-be smokers with new products including so called reduced tar filter cigarettes. In a study from Boston, investigators studied men and women who had either never smoked or former smokers who were currently smoking a specific brand of cigarette when they were enrolled in the Cancer Prevention Study. The results of this study suggest that, irrespective of the tar level of the current brand being smoked, all current smokers had a far greater risk of lung cancer than people who had stopped smoking or who had never smoked. Moreover, the increase in lung cancer risk was similar in people who smoked medium tar cigarettes, low tar cigarettes, or very low tar cigarettes. Men and women who smoked non-filtered cigarettes with very high tar ratings have the highest risk of lung cancer, however. ( BMJ 2004;328:72–6)

    It is well known that the risk of anterior ischaemic optic neuropathy is related to the so called disc at risk (with little or no optic cup). There have been reports suggesting that optic nerve head drusen may be a risk factor for developing anterior ischaemic optic neuropathy. In a report from Indiana clinicians have described 20 patients with anterior ischaemic neuropathy with optic disc drusen. In this study patients were strikingly similar to those with non-arteritic anterior ischaemic optic neuropathy unassociated with drusen with regard to prevalence of vascular risk factors, pattern visual field loss, and occurrence of subsequent similar event in the fellow eye. However, it is noteworthy that patients with optic nerve head drusen and anterior ischaemic optic neuropathy were younger than those with non-arteritic anterior ischaemic neuropathy and no drusen. ( Archives of Ophthalmology 2004;122:48–53)(Editor)