Nyhetsinnsamler

Suppressing old memories key to learning new ones

nobel intent - lør, 28/03/2015 - 22:05

There has long been convincing evidence that recalling a memory can cause changes in that memory, potentially weakening it, strengthening it, or otherwise altering it. A new study, published in Nature Neuroscience by researchers from the University of Birmingham, the MRC Cognition and Brain Sciences Unit, and the Behavioral and Clinical Neurosciences Institute, presents a convincing argument that the weakening of old memories may be an adaptive function, one that helps the brain integrate new memories with existing ones.

The researchers were able to watch subjects’ brain activity as memories were recalled using a functional Magnetic Resonance Imaging (fMRI) machine. An fMRI machine allows scientists to see changes in brain activity by producing images that show where oxygen-rich blood is flowing within the brain.

Subjects were shown 144 pairs of pictures/words while in the fMRI machine, and their brain activity was observed. Then, the subjects entered a learning phase, in which they were trained on 72 picture-word pairs, a subset of the initial 144. They were asked to construct a highly detailed association between the pictures and the words, using intricate mental imagery. They were then asked to learn a second set of associations for each word; these served as competition for the first set.

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[Editorial] Dementia: turning fine aspirations into measurable progress

The Lancet - lør, 28/03/2015 - 01:00
“I look young, but I am actually quite old”, pronounced WHO Director-General Margaret Chan at the first Ministerial Conference on Global Action Against Dementia, hosted by WHO, the Organisation for Economic Co-operation and Development (OECD), and the UK Department of Health in Geneva on March 16–17. Dr Chan continued, with great clarity and sincerity, to describe her own desire to grow old gracefully and with dignity, contrasting her own aspirations with the plight of 47 million people worldwide who struggle to cope with the debilitating effect of dementia, a disorder that is expected to double in prevalence over the next two decades, and that comes with an estimated health bill worldwide in excess of US$600 billion.

[Editorial] 1 year on—lessons from the Ebola outbreak for WHO

The Lancet - lør, 28/03/2015 - 01:00
This week has seen what is likely to be the beginning of an onslaught of criticism levelled against WHO for its handling of the Ebola outbreak in west Africa. First, ahead of the 1-year anniversary of the outbreak's start, an article by the Associated Press (AP) reported that WHO deliberately delayed declaring the Ebola epidemic as an emergency in early June, 2014, waiting instead until Aug 8 to finally make the announcement. AP obtained internal emails and documents suggesting that senior WHO officials were not only told of the desperate situation, but also received anguished pleas for help.

[Editorial] Perinatal mental health—towards a robust system of care

The Lancet - lør, 28/03/2015 - 01:00
The experiences of pregnancy and birth transform the lives of mothers and their families. Caring for children has the potential to enrich the lives of all involved, but accompanying health and social challenges are common. As discussed in a recent Lancet Series on perinatal mental health, perinatal depression, for example, occurs in an estimated 6·5–12·9% of mothers at different stages of pregnancy and during the year after birth. The financial costs of perinatal mental disorders, estimated at more than £8 billion in the UK for each annual cohort, are a scant reflection of their effect on the wellbeing of affected parents, and that of children at a vulnerable stage in their development.

[Comment] A new social contract for medical innovation

The Lancet - lør, 28/03/2015 - 01:00
Despite burgeoning knowledge about the origins of disease founded on scientific advances, there are increasing public concerns that medical innovation is not helping patients in need fast enough. In the UK, Lord Saatchi's proposal for a Medical Innovation Bill1 is one manifestation of this concern, while the Minister for Life Sciences' current Innovative Medicines and Medical Technologies Review is another.2 A review of medical innovation is timely; it is not just the time taken for research, but the rising cost of drug development that demand attention.

[Comment] The outlook for public spending on the National Health Service

The Lancet - lør, 28/03/2015 - 01:00
During the current UK Parliament of 2010–15, although total spending by government departments on public services has been cut by an average of about 10%, the Department of Health has seen its budget increased by more than 6%.1 This favourable treatment has increased the severity of the financial squeeze on other departments, with many having seen their budgets cut by 20% or more in just 5 years. In 2009–10, the Department of Health accounted for just over a quarter of all departmental spending, but in 2015–16 it is expected to account for nearly a third.

[Comment] Offline: What is the point of scientific publishing?

The Lancet - lør, 28/03/2015 - 01:00
On March 6, 1665, Henry Oldenburg published the inaugural issue of Philosophical Transactions. The world's most famous scientific journal was licensed by the Royal Society, a new, radical, and even subversive organisation. Oldenburg put it well in a letter to a German theologian and physician called Leichner in 1663—“the Royal Society says it is not its concern to have any knowledge of scholastic and theological matters, for its sole business is to cultivate knowledge of nature and useful arts by means of observation and experiment, and to promote them for the safeguarding and convenience of human life”.

[World Report] Republicans' bills target science at US environment agency

The Lancet - lør, 28/03/2015 - 01:00
Proposed legislation would change how the US Environmental Protection Agency uses science to determine pollution limits. The Lancet's Washington correspondent Susan Jaffe reports.

[Perspectives] Will politicians be architects or destroyers of the NHS?

The Lancet - lør, 28/03/2015 - 01:00
In the history of the UK's National Health Service (NHS), the Health and Social Care Act 2012 will go down as the most egregious act of vandalism against the people of England. During its passage through Parliament, David Owen called it the “Secretary of State's Abdication Bill”, because the legislation removed the Secretary of State for Health's responsibility for, and duty to provide, an NHS throughout England. The Act's destructive effect is being felt in all political jurisdictions. But it has fallen to Owen, a peer in the House of Lords who describes himself as an independent social democrat, to take on the mantle of Nye Bevan, the founding father of the NHS.

[Perspectives] Exotic enchantments

The Lancet - lør, 28/03/2015 - 01:00
As any enchanted visitor knows, the Pitt Rivers Museum in Oxford, UK, is a Victorian cavern stuffed with intriguing objects. In the medical field, its large amulet collection (originally assembled by Sir Henry Wellcome) contains a miniature dark-coloured skeleton hanging from a gallows. Purchased in Paris in 1899, this locket symbolised a belief that the tools of execution—and indeed fragments from the corpses of criminals—had the power to cure disease and bring luck. Another object, of brass and steel, with a razor-shaped blade, was donated in 1914 by a colonial civil surgeon working in Firozpur, a military town in India.

[Perspectives] Sheena McCormack: helping to prepare the world for PrEP

The Lancet - lør, 28/03/2015 - 01:00
As a clinician who has witnessed the devastating impact of the HIV/AIDS epidemic since the 1980s, Sheena McCormack is enthusiastic about her latest project, the UK Medical Research Council (MRC) PROUD study. As lead investigator, she has been investigating the effect of pre-exposure prophylaxis (PrEP) to protect against HIV infection in high-risk men who have sex with men (MSM). PROUD has shown that PrEP reduces new HIV infections by 86%. “These results show that MSM who know they are at high risk of HIV are willing to take PrEP and it works incredibly well at preventing HIV infection in the real world”, says McCormack, who works at University College London and is a Professor of Clinical Epidemiology at Imperial College London.

[Obituary] Wayne Jay Katon

The Lancet - lør, 28/03/2015 - 01:00
Psychiatrist and pioneer of US collaborative care. Born in Brooklyn, NY, USA, on Sept 14, 1950, he died from lymphoma in Seattle, WA, USA, on March 1, 2015.

[Correspondence] GBD 2013 and HIV incidence in high income countries

The Lancet - lør, 28/03/2015 - 01:00
The analyses from the Global Burden of Disease (GBD) Study 2013 reported new estimates of HIV incidence, by country.1 Here, we provide strong evidence that the GBD estimates are not correct and systematically underestimate HIV transmission, particularly in high-income countries.

[Correspondence] What are affordable vaccines?

The Lancet - lør, 28/03/2015 - 01:00
I read with interest the Lancet Editorial, “What are affordable vaccines?” (Jan 24, p 304)1 commenting on the 2015 report of Médecins Sans Frontières (MSF).2 Although I appreciate and support the attention given to the immunisation of the poor, I was disappointed that the main and sole message of the 124 page report is that the price of vaccines and the focus on profit of the vaccine industry prevent the delivery of additional vaccines to the poor. I have been designing and developing vaccines in an industrial environment for a long time and I know that the vaccine industry is driven by committed and passionate people, who care and are proud of developing new vaccines that save lives globally.

[Correspondence] Diagnosis of reversible causes of coma

The Lancet - lør, 28/03/2015 - 01:00
We read with great interest the Review (Dec 6, p 2064)1 about the diagnosis of reversible causes of coma. Jonathan Edlow and colleagues,1 however, neglected to include in their Review reversible coma caused by the bite of the Elapidae family of venomous snakes (cobra and krait).

[Correspondence] Diagnosis of reversible causes of coma

The Lancet - lør, 28/03/2015 - 01:00
The management of a patient with impaired consciousness requires a rigorous approach, hence, Jonathan Edlow and colleagues' proposal for an algorithm of diagnosis and list of reversible causes of coma.1 However, in our opinion, one cause of reversible coma is missing: limbic encephalitis. This cause is often known to present with a set of three symptoms: epilepsy, amnesia, and psychiatric problems.2–4 The evolution of this disorder is progressive and can be confused with a psychiatric disorder, which can result in a delayed diagnosis.

[Correspondence] Diagnosis of reversible causes of coma

The Lancet - lør, 28/03/2015 - 01:00
In their comprehensive Review on the diagnosis of reversible causes of coma, Jonathan Edlow and colleagues1 did not consider two clinically relevant, curable types of metabolic coma due to diffuse neuronal dysfunction of metabolic origin: D-lactic acidosis and niacin deficiency.

[Correspondence] Diagnosis of reversible causes of coma – Authors' reply

The Lancet - lør, 28/03/2015 - 01:00
We thank the respondents for their comments on our Review1 on reversible causes of coma.

[Correspondence] Effects of intensive glycaemic control on ischaemic heart disease

The Lancet - lør, 28/03/2015 - 01:00
In this post-hoc analysis of the ACCORD study (Nov 29, p 1936),1 Hertzel Gerstein and colleagues have reported on the effectiveness of intensive glycaemic control for ischaemic heart disease in patients with type 2 diabetes and other coronary risk factors. Although the ACCORD trial has yielded many important findings for the management of type 2 diabetes, its results should be carefully interpreted from various perspectives. The previous report of the ACCORD trial2 reported that intensive glucose lowering results in increased deaths from cardiovascular and other causes; from a clinical point of view, that study presented more important results than the present study.

[Correspondence] Effects of intensive glycaemic control on ischaemic heart disease – Authors' reply

The Lancet - lør, 28/03/2015 - 01:00
Our Article1 reported that intensive versus standard glycaemia control reduced several measures of ischaemic heart disease that were collected during the ACCORD trial. Tetsuro Tsujimoto and Ritsuko Yamamoto-Honda correctly point out that such an analysis could yield biased results if it does not account for mortality differences between groups. That is why we explicitly dealt with this possibility in three ways. First, all of our analyses explicitly accounted for the competing risk of death to reduce the probability that the results were only applicable to the survivors.