Riviste scientifiche

A Global Champion for Health—WHO’s Next?

PLoS Medicine - Ma, 28/06/2016 - 23:00

by The PLOS Medicine Editors

In this month’s editorial, the PLOS Medicine Editors propose ideal qualities for the World Health Organization's next Director General, for whom the selection process is now underway.

Guidelines for Accurate and Transparent Health Estimates Reporting: the GATHER statement

PLoS Medicine - Ma, 28/06/2016 - 23:00

by Gretchen A. Stevens, Leontine Alkema, Robert E. Black, J. Ties Boerma, Gary S. Collins, Majid Ezzati, John T. Grove, Daniel R. Hogan, Margaret C. Hogan, Richard Horton, Joy E. Lawn, Ana Marušić, Colin D. Mathers, Christopher J. L. Murray, Igor Rudan, Joshua A. Salomon, Paul J. Simpson, Theo Vos, Vivian Welch, The GATHER Working Group

Gretchen Stevens and colleagues present the GATHER statement, which seeks to promote good practice in the reporting of global health estimates.

Weighing Evidence from Mendelian Randomization—Early-Life Obesity as a Causal Factor in Multiple Sclerosis?

PLoS Medicine - Ma, 28/06/2016 - 23:00

by Alberto Ascherio, Kassandra L. Munger

In this Perspective, Alberto Ascherio and Kassandra Munger discuss the implications of Richards and colleagues' study exploring the role of early-life obesity in risk of multiple sclerosis.

Obesity and Multiple Sclerosis: A Mendelian Randomization Study

PLoS Medicine - Ma, 28/06/2016 - 23:00

by Lauren E. Mokry, Stephanie Ross, Nicholas J. Timpson, Stephen Sawcer, George Davey Smith, J. Brent Richards

Background

Observational studies have reported an association between obesity, as measured by elevated body mass index (BMI), in early adulthood and risk of multiple sclerosis (MS). However, bias potentially introduced by confounding and reverse causation may have influenced these findings. Therefore, we elected to perform Mendelian randomization (MR) analyses to evaluate whether genetically increased BMI is associated with an increased risk of MS.

Methods and Findings

Employing a two-sample MR approach, we used summary statistics from the Genetic Investigation of Anthropometric Traits (GIANT) consortium and the International MS Genetics Consortium (IMSGC), the largest genome-wide association studies for BMI and MS, respectively (GIANT: n = 322,105; IMSGC: n = 14,498 cases and 24,091 controls). Seventy single nucleotide polymorphisms (SNPs) were genome-wide significant (p < 5 x 10−8) for BMI in GIANT (n = 322,105) and were investigated for their association with MS risk in the IMSGC. The effect of each SNP on MS was weighted by its effect on BMI, and estimates were pooled to provide a summary measure for the effect of increased BMI upon risk of MS. Our results suggest that increased BMI influences MS susceptibility, where a 1 standard deviation increase in genetically determined BMI (kg/m2) increased odds of MS by 41% (odds ratio [OR]: 1.41, 95% CI 1.20–1.66, p = 2.7 x 10−5, I2 = 0%, 95% CI 0–29). Sensitivity analyses, including MR-Egger regression, and the weighted median approach provided no evidence of pleiotropic effects. The main study limitations are that, while these sensitivity analyses reduce the possibility that pleiotropy influenced our results, residual pleiotropy is difficult to exclude entirely.

Conclusion

Genetically elevated BMI is associated with risk of MS, providing evidence for a causal role for obesity in MS etiology. While obesity has been associated with many late-life outcomes, these findings suggest an important consequence of childhood and/or early adulthood obesity.

The Effect of Sitagliptin on Carotid Artery Atherosclerosis in Type 2 Diabetes: The PROLOGUE Randomized Controlled Trial

PLoS Medicine - Ma, 28/06/2016 - 23:00

by Jun-ichi Oyama, Toyoaki Murohara, Masafumi Kitakaze, Tomoko Ishizu, Yasunori Sato, Kazuo Kitagawa, Haruo Kamiya, Masayoshi Ajioka, Masaharu Ishihara, Kazuoki Dai, Mamoru Nanasato, Masataka Sata, Koji Maemura, Hirofumi Tomiyama, Yukihito Higashi, Kohei Kaku, Hirotsugu Yamada, Munehide Matsuhisa, Kentaro Yamashita, Yasuko K. Bando, Naoki Kashihara, Shinichiro Ueda, Teruo Inoue, Atsushi Tanaka, Koichi Node, PROLOGUE Study Investigators

Background

Experimental studies have suggested that dipeptidyl peptidase-4 (DPP-4) inhibitors provide cardiovascular protective effects. We performed a randomized study to evaluate the effects of sitagliptin added on to the conventional therapy compared with conventional therapy alone (diet, exercise, and/or drugs, except for incretin-related agents) on the intima-media thickness (IMT) of the carotid artery, a surrogate marker for the evaluation of atherosclerotic cardiovascular disease, in people with type 2 diabetes mellitus (T2DM).

Methods and Findings

We used a multicenter PROBE (prospective, randomized, open label, blinded endpoint) design. Individuals aged ≥30 y with T2DM (6.2% ≤ HbA1c < 9.4%) were randomly allocated to receive either sitagliptin (25 to 100 mg/d) or conventional therapy. Carotid ultrasound was performed at participating medical centers, and all parameters were measured in a core laboratory. Of the 463 enrolled participants with T2DM, 442 were included in the primary analysis (sitagliptin group, 222; conventional therapy group, 220). Estimated mean (± standard error) common carotid artery IMT at 24 mo of follow-up in the sitagliptin and conventional therapy groups was 0.827 ± 0.007 mm and 0.837 ± 0.007 mm, respectively, with a mean difference of −0.009 mm (97.2% CI −0.028 to 0.011, p = 0.309). HbA1c level at 24 mo was significantly lower with sitagliptin than with conventional therapy (6.56% ± 0.05% versus 6.72% ± 0.05%, p = 0.008; group mean difference −0.159, 95% CI −0.278 to −0.041). Episodes of serious hypoglycemia were recorded only in the conventional therapy group, and the rate of other adverse events was not different between the two groups. As it was not a placebo-controlled trial and carotid IMT was measured as a surrogate marker of atherosclerosis, there were some limitations of interpretation.

Conclusions

In the PROLOGUE study, there was no evidence that treatment with sitagliptin had an additional effect on the progression of carotid IMT in participants with T2DM beyond that achieved with conventional treatment.

Trial Registration

University Hospital Medical Information Network Clinical Trials Registry UMIN000004490

Malaria Epidemiology in Kilifi, Kenya during the 21st Century: What Next?

PLoS Medicine - Ma, 28/06/2016 - 23:00

by Lorenz von Seidlein, Jakob Knudsen

Lorenz von Seidlein and Jakob Knudsen discuss the changes in malaria incidence recorded at a single site in Africa over 25 years, along with future implications for disease prevention.

Age, Spatial, and Temporal Variations in Hospital Admissions with Malaria in Kilifi County, Kenya: A 25-Year Longitudinal Observational Study

PLoS Medicine - Ma, 28/06/2016 - 23:00

by Polycarp Mogeni, Thomas N. Williams, Gregory Fegan, Christopher Nyundo, Evasius Bauni, Kennedy Mwai, Irene Omedo, Patricia Njuguna, Charles R. Newton, Faith Osier, James A. Berkley, Laura L. Hammitt, Brett Lowe, Gabriel Mwambingu, Ken Awuondo, Neema Mturi, Norbert Peshu, Robert W. Snow, Abdisalan Noor, Kevin Marsh, Philip Bejon

Background

Encouraging progress has been seen with reductions in Plasmodium falciparum malaria transmission in some parts of Africa. Reduced transmission might lead to increasing susceptibility to malaria among older children due to lower acquired immunity, and this has implications for ongoing control strategies.

Methods and Findings

We conducted a longitudinal observational study of children admitted to Kilifi County Hospital in Kenya and linked it to data on residence and insecticide-treated net (ITN) use. This included data from 69,104 children aged from 3 mo to 13 y admitted to Kilifi County Hospital between 1 January 1990 and 31 December 2014. The variation in malaria slide positivity among admissions was examined in logistic regression models using the following predictors: location of the residence, calendar time, the child’s age, ITN use, and the enhanced vegetation index (a proxy for soil moisture). The proportion of malaria slide-positive admissions declined from 0.56 (95% confidence interval [CI] 0.54–0.58) in 1998 to 0.07 (95% CI 0.06–0.08) in 2009 but then increased again through to 0.24 (95% CI 0.22–0.25) in 2014. Older children accounted for most of the increase after 2009 (0.035 [95% CI 0.030–0.040] among young children compared to 0.22 [95% CI 0.21–0.23] in older children). There was a nonlinear relationship between malaria risk and prevalence of ITN use within a 2 km radius of an admitted child’s residence such that the predicted malaria positive fraction varied from ~0.4 to <0.1 as the prevalence of ITN use varied from 20% to 80%. In this observational analysis, we were unable to determine the cause of the decline in malaria between 1998 and 2009, which pre-dated the dramatic scale-up in ITN distribution and use.

Conclusion

Following a period of reduced transmission, a cohort of older children emerged who have increased susceptibility to malaria. Further reductions in malaria transmission are needed to mitigate the increasing burden among older children, and universal ITN coverage is a promising strategy to achieve this goal.

Agreements between Industry and Academia on Publication Rights: A Retrospective Study of Protocols and Publications of Randomized Clinical Trials

PLoS Medicine - Ma, 28/06/2016 - 23:00

by Benjamin Kasenda, Erik von Elm, John J. You, Anette Blümle, Yuki Tomonaga, Ramon Saccilotto, Alain Amstutz, Theresa Bengough, Joerg J. Meerpohl, Mihaela Stegert, Kelechi K. Olu, Kari A. O. Tikkinen, Ignacio Neumann, Alonso Carrasco-Labra, Markus Faulhaber, Sohail M. Mulla, Dominik Mertz, Elie A. Akl, Dirk Bassler, Jason W. Busse, Ignacio Ferreira-González, Francois Lamontagne, Alain Nordmann, Viktoria Gloy, Heike Raatz, Lorenzo Moja, Shanil Ebrahim, Stefan Schandelmaier, Xin Sun, Per O. Vandvik, Bradley C. Johnston, Martin A. Walter, Bernard Burnand, Matthias Schwenkglenks, Lars G. Hemkens, Heiner C. Bucher, Gordon H. Guyatt, Matthias Briel

Background

Little is known about publication agreements between industry and academic investigators in trial protocols and the consistency of these agreements with corresponding statements in publications. We aimed to investigate (i) the existence and types of publication agreements in trial protocols, (ii) the completeness and consistency of the reporting of these agreements in subsequent publications, and (iii) the frequency of co-authorship by industry employees.

Methods and Findings

We used a retrospective cohort of randomized clinical trials (RCTs) based on archived protocols approved by six research ethics committees between 13 January 2000 and 25 November 2003. Only RCTs with industry involvement were eligible. We investigated the documentation of publication agreements in RCT protocols and statements in corresponding journal publications. Of 647 eligible RCT protocols, 456 (70.5%) mentioned an agreement regarding publication of results. Of these 456, 393 (86.2%) documented an industry partner’s right to disapprove or at least review proposed manuscripts; 39 (8.6%) agreements were without constraints of publication. The remaining 24 (5.3%) protocols referred to separate agreement documents not accessible to us. Of those 432 protocols with an accessible publication agreement, 268 (62.0%) trials were published. Most agreements documented in the protocol were not reported in the subsequent publication (197/268 [73.5%]). Of 71 agreements reported in publications, 52 (73.2%) were concordant with those documented in the protocol. In 14 of 37 (37.8%) publications in which statements suggested unrestricted publication rights, at least one co-author was an industry employee. In 25 protocol-publication pairs, author statements in publications suggested no constraints, but 18 corresponding protocols documented restricting agreements.

Conclusions

Publication agreements constraining academic authors’ independence are common. Journal articles seldom report on publication agreements, and, if they do, statements can be discrepant with the trial protocol.

Beautifully preserved feathers belonged to tiny flying dinosaurs

New Scientist - Ma, 28/06/2016 - 17:00
Detailed amber fossils of wings from dinosaurs just 3.5 centimetres long suggest they flew like today’s birds. Such finds let us probe how flight evolved

Zika vaccine protects mice, but may increase risk of dengue

New Scientist - Ma, 28/06/2016 - 17:00
One dose protects mice from Zika but may put people at greater risk of dengue. A more targeted approach may protect against both diseases

Strange ‘dark hydrogen’ may exist deep inside giant gas planets

New Scientist - Ma, 28/06/2016 - 14:15
Experiments on Earth reveal a new state of hydrogen that doesn’t reflect or absorb light – which could explain how planets like Jupiter cooled after formation

Huge newfound deposit of helium will keep MRI scanners running

New Scientist - Ma, 28/06/2016 - 00:30
Helium prospectors have uncovered a massive source of the vanishing gas, vital for MRI scanners, the Large Hadron Collider, NASA rocket fuel… and balloons

Angry scientists must fight to pick up the pieces after Brexit

New Scientist - Lu, 27/06/2016 - 18:46
Brexit is the heartbreaking outcome of a misinformed debate. Scientists must fight to pick up the pieces, says Mike Galsworthy

Supreme Court strikes down abortion restrictions in Texas

New Scientist - Lu, 27/06/2016 - 17:54
In a major victory for pro-choice advocates, the US Supreme Court struck down a Texas abortion law today

Sexing it app: The erotic video games that explore sexuality

New Scientist - Lu, 27/06/2016 - 17:27
So many films and books involve sex scenes, so why not games? These interactive experiences can deal with serious issues in a way that’s more than just pushing buttons

People who meditate are more aware of their unconscious brain

New Scientist - Lu, 27/06/2016 - 14:38
A twist on the famous Libet free will experiments suggests that people who meditate have more access to the unconscious brain

China plans for space station with most powerful rocket launch

New Scientist - Lu, 27/06/2016 - 13:49
The country has just tested its new Long March-7 rocket and a prototype version of its next-generation crew capsule ahead of its planned space station

How the size and shape of your glass affects how much you drink

New Scientist - Lu, 27/06/2016 - 13:40
You drink more slowly from a straight glass than a curved one, but more quickly from a large glass than a small one – effects your local pub might by exploiting

Shampoo bottles get nano-makeover to squeeze out every drop

New Scientist - Lu, 27/06/2016 - 12:46
Wash and go: Plastic embedded with silica molecules repels sludgy hair products so that every last blob slides out of the bottle, even without you shaking it  

[Editorial] Organ donation depends on trust

The Lancet - Sa, 25/06/2016 - 00:00
Last week, the White House announced public–private initiatives to help shorten the waiting list for organ transplantation in the USA, on which 120 000 people currently sit in need of a kidney, liver, heart, or lung. 7000 of them will die waiting this year. The gap between supply and demand continues to grow. That 95% of Americans are believed to support organ donation but only 50% have signed up means there is considerable need for change in how we assure organ supply.
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