BMJ  2006;332:802 (1 April), doi:10.1136/bmj.332.7544.802

Minerva

Minerva

People with high blood pressure are at increased risk of developing Alzheimer's disease, so perhaps it's not very remarkable that, in a study of an elderly population in Utah, use of antihypertensive drugs tended to reduce the risk (Archives of Neurology 2006;63: doi: 10.1001/archneur.63.5.noc60013[Abstract/Free Full Text]). More interesting was the observation that different treatments varied in their protective effect. Diuretics, particularly potassium sparing diuretics, conferred the most protection. The investigators point out that, whereas both loop and thiazide diuretics reduce plasma potassium concentration, potassium sparing diuretics usually lead to increased concentrations.

Waste water flowing out of hospitals is potentially dangerous stuff. Out of a total of 38 samples taken from the main sewer of a French university hospital over a two year period, 31 were positive in at least one microbiological assay of genotoxicity. Samples taken on a Monday and during periods of low rainfall were most likely to show evidence of toxicity. Which of the many thousands of chemical compounds released from hospitals are to blame has yet to be established, but the researchers rate anticancer drugs and antimicrobials as prime suspects (Annals of Occupational Hygiene 2006;50: 189-96[Abstract/Free Full Text]).

Minerva has a short attention span and sometimes finds articles in the New York Review of Books heavy going. But she was gripped by a piece in the current issue (2006; March 23: 38-43) on the healthcare crisis in the US. It reaches the striking conclusion that, in the end, the US may have to settle on a system of national health insurance with a lot of direct government provision of health care, simply because nothing else works. At a time when many of the attempts to reform the UK's National Health Service seem to be inspired by US ideas, she hopes the article will be widely read.

Postoperative ileus is common after abdominal surgery, and a safe and simple way of speeding up the recovery of normal intestinal function would improve patients' comfort and save hospitals time and money. A small trial in people who had an elective resection of the sigmoid colon suggests that chewing gum might be the answer. Compared with the control group, time to first passage of flatus and duration of hospital stay were substantially less among patients given sugarless gum to chew (Archives of Surgery 2006;141: 174-6[Abstract/Free Full Text]).

La belle indifférence has been considered a classic feature of hysterical conversion syndromes since the time of Freud. The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders defines it as "a relative lack of concern about the nature or implications of the symptoms"—though "relative to what?" one wonders. But a systematic review of studies comparing its prevalence among patients with conversion symptoms with that among patients with organic disease found little difference. The authors suggest that, despite its attractive name, la belle indifférence should be abandoned as a clinical sign (British Journal of Psychiatry 2006;188: 204-9[Abstract/Free Full Text]).

For the past 30 years, biologists have viewed the heart as a postmitotic organ—by which they mean that its complement of cardiomyocytes is fixed during early development and that, while these cells can hypertrophy, they cannot divide or be replaced. However, cardiac stem cells have now been found in the hearts of small and large adult mammals, including humans. An article in Circulation (2006;113: 1451-63[Free Full Text]) argues that it's time to abandon the old dogma and think of the heart as a highly dynamic organ in which old, poorly functioning myocytes are continuously replaced. Understanding how the turnover of cardiac cells is regulated might suggest new ways to stimulate cardiac repair.

The human eye loses its ability to accommodate by the age of 55 or so, largely because the ciliary muscle is no longer able to change the shape of the increasingly hard crystalline lens. Various ways of restoring focusing ability have been tried. One idea is to fill the lens capsule with a viscoelastic substance with the same optical and mechanical properties of the young lens. Another is to position an intraocular lens implant in such a way that contraction and relaxation of the ciliary muscle moves it along the anteroposterior axis of the eye (Investigative Ophthalmology and Visual Science 2006;47: 1230-5[Abstract/Free Full Text]). Despite the ingenuity of this approach, the accommodative response so far is only about 1 dioptre.

People tend to be either larks or owls, or, as sleep researchers prefer to put it, morning or evening chronotypes. But what determines these preferences? An epidemiological survey of several thousand New Zealand adults found that preference for "morningness/eveningness" was largely independent of ethnicity, sex, and socioeconomic position. Indeed, the researchers failed to come up with any strong associations at all except for the unsurprising fact that night workers were more likely to be evening types (Journal of Biological Rhythms 2006;21: 68-76[Abstract/Free Full Text]).

Most x ray contrast agents are based on organic compounds of iodine. They tend to be cleared from the circulation rapidly, so imaging times are short and arterial catheterisation is often necessary. Nanoparticles of gold may work better. Gold has a higher atomic number than iodine and, weight for weight, provides nearly three times as much contrast. So far, it has been tried only in mice, but, to a non-expert eye, the images look impressively clear (British Journal of Radiology 2006;79: 248-53[Abstract/Free Full Text]).

Benign essential tremor is often embarrassing and may be more disabling than its name suggests. blockers and primidone can be effective treatments, but their use is limited by side effects. A recent randomised controlled trial indicates that the antiepileptic drug topiramate may also be helpful both in reducing the severity of the tremor and in improving function (Neurology 2006;66: 672-7[Abstract/Free Full Text]). However, more than a third of participants in the active arm stopped treatment before completion of the trial—mainly because of adverse events.

Osteogenesis imperfecta is an inherited disorder characterised by increased bone fragility and progressive bone deformity. Cyclical treatment with disodium pamidronate reduces osteoclast-mediated bone resorption, improves bone mineralisation, decreases pain and the incidence of fracture, and produces multiple sclerotic growth recovery lines in long bones, which are visible on x ray. The amount of bone growth between doses can be estimated from the distance between these lines. Debasis Chakravarty, staff orthopaedic surgeon (debasischakravarty{at}hotmail.com), Samarth Chopra, senior house officer, Jonathon Jones, consultant orthopaedic surgeon, Peterborough District General Hospital, Peterborough PE3 6DA

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