Riviste scientifiche

Modern lifestyles shaped our evolution only a few thousand years ago

New Scientist - %age fa
Two new studies reveal recent evolutionary changes in Europe and East Asia, suggesting that modern living can change our immune systems and metabolism

There is no fundamental difference between male and female brains

New Scientist - %age fa
A lasting desire to find differences in how male and female brains work serves to affirm gender stereotypes, not explain them, says Dean Burnett

Machine learning assessment of myocardial ischemia using angiography: Development and retrospective validation

PLoS Medicine - Ma, 13/11/2018 - 23:00

by Hyeonyong Hae, Soo-Jin Kang, Won-Jang Kim, So-Yeon Choi, June-Goo Lee, Youngoh Bae, Hyungjoo Cho, Dong Hyun Yang, Joon-Won Kang, Tae-Hwan Lim, Cheol Hyun Lee, Do-Yoon Kang, Pil Hyung Lee, Jung-Min Ahn, Duk-Woo Park, Seung-Whan Lee, Young-Hak Kim, Cheol Whan Lee, Seong-Wook Park, Seung-Jung Park

Background

Invasive fractional flow reserve (FFR) is a standard tool for identifying ischemia-producing coronary stenosis. However, in clinical practice, over 70% of treatment decisions still rely on visual estimation of angiographic stenosis, which has limited accuracy (about 60%–65%) for the prediction of FFR < 0.80. One of the reasons for the visual–functional mismatch is that myocardial ischemia can be affected by the supplied myocardial size, which is not always evident by coronary angiography. The aims of this study were to develop an angiography-based machine learning (ML) algorithm for predicting the supplied myocardial volume for a stenosis, as measured using coronary computed tomography angiography (CCTA), and then to build an angiography-based classifier for the lesions with an FFR < 0.80 versus ≥ 0.80.

Methods and findings

A retrospective study was conducted using data from 1,132 stable and unstable angina patients with 1,132 intermediate lesions who underwent invasive coronary angiography, FFR, and CCTA at the Asan Medical Center, Seoul, Korea, between 1 May 2012 and 30 November 2015. The mean age was 63 ± 10 years, 76% were men, and 72% of the patients presented with stable angina. Of these, 932 patients (assessed before 31 January 2015) constituted the training set for the algorithm, and 200 patients (assessed after 1 February 2015) served as a test cohort to validate its diagnostic performance. Additionally, external validation with 79 patients from two centers (CHA University, Seongnam, Korea, and Ajou University, Suwon, Korea) was conducted. After automatic contour calibration using the caliber of guiding catheter, quantitative coronary angiography was performed using the edge-detection algorithms (CAAS-5, Pie-Medical). Clinical information was provided by the Asan BiomedicaL Research Environment (ABLE) system. The CCTA-based myocardial segmentation (CAMS)-derived myocardial volume supplied by each vessel (right coronary artery [RCA], left anterior descending [LAD], left circumflex [LCX]) and the myocardial volume subtended to a stenotic segment (CAMS-%Vsub) were measured for labeling. The ML for (1) predicting vessel territories (CAMS-%LAD, CAMS-%LCX, and CAMS-%RCA) and CAMS-%Vsub and (2) identifying the lesions with an FFR < 0.80 was constructed. Angiography-based ML, employing a light gradient boosting machine (GBM), showed mean absolute errors (MAEs) of 5.42%, 8.57%, and 4.54% for predicting CAMS-%LAD, CAMS-%LCX, and CAMS-%RCA, respectively. The percent myocardial volumes predicted by ML were used to predict the CAMS-%Vsub. With 5-fold cross validation, the MAEs between ML-predicted percent myocardial volume subtended to a stenotic segment (ML-%Vsub) and CAMS-%Vsub were minimized by the elastic net (6.26% ± 0.55% for LAD, 5.79% ± 0.68% for LCX, and 2.95% ± 0.14% for RCA lesions). Using all attributes (age, sex, involved vessel segment, and angiographic features affecting the myocardial territory and stenosis degree), the ML classifiers (L2 penalized logistic regression, support vector machine, and random forest) predicted an FFR < 0.80 with an accuracy of approximately 80% (area under the curve [AUC] = 0.84–0.87, 95% confidence intervals 0.71–0.94) in the test set, which was greater than that of diameter stenosis (DS) > 53% (66%, AUC = 0.71, 95% confidence intervals 0.65–0.78). The external validation showed 84% accuracy (AUC = 0.89, 95% confidence intervals 0.83–0.95). The retrospective design, single ethnicity, and the lack of clinical outcomes may limit this prediction model’s generalized application.

Conclusion

We found that angiography-based ML is useful to predict subtended myocardial territories and ischemia-producing lesions by mitigating the visual–functional mismatch between angiographic and FFR. Assessment of clinical utility requires further validation in a large, prospective cohort study.

Transforming health policy through machine learning

PLoS Medicine - Ma, 13/11/2018 - 23:00

by Hutan Ashrafian, Ara Darzi

In their Perspective, Ara Darzi and Hutan Ashrafian give us a tour of the future policymaker's machine learning toolkit.

Machine learning to identify pairwise interactions between specific IgE antibodies and their association with asthma: A cross-sectional analysis within a population-based birth cohort

PLoS Medicine - Ma, 13/11/2018 - 23:00

by Sara Fontanella, Clément Frainay, Clare S. Murray, Angela Simpson, Adnan Custovic

Background

The relationship between allergic sensitisation and asthma is complex; the data about the strength of this association are conflicting. We propose that the discrepancies arise in part because allergic sensitisation may not be a single entity (as considered conventionally) but a collection of several different classes of sensitisation. We hypothesise that pairings between immunoglobulin E (IgE) antibodies to individual allergenic molecules (components), rather than IgE responses to ‘informative’ molecules, are associated with increased risk of asthma.

Methods and findings

In a cross-sectional analysis among 461 children aged 11 years participating in a population-based birth cohort, we measured serum-specific IgE responses to 112 allergen components using a multiplex array (ImmunoCAP Immuno‑Solid phase Allergy Chip [ISAC]). We characterised sensitivity to 44 active components (specific immunoglobulin E [sIgE] > 0.30 units in at least 5% of children) among the 213 (46.2%) participants sensitised to at least one of these 44 components. We adopted several machine learning methodologies that offer a powerful framework to investigate the highly complex sIgE–asthma relationship. Firstly, we applied network analysis and hierarchical clustering (HC) to explore the connectivity structure of component-specific IgEs and identify clusters of component-specific sensitisation (‘component clusters’). Of the 44 components included in the model, 33 grouped in seven clusters (C.sIgE-1–7), and the remaining 11 formed singleton clusters. Cluster membership mapped closely to the structural homology of proteins and/or their biological source. Components in the pathogenesis-related (PR)-10 proteins cluster (C.sIgE-5) were central to the network and mediated connections between components from grass (C.sIgE-4), trees (C.sIgE-6), and profilin clusters (C.sIgE-7) with those in mite (C.sIgE-1), lipocalins (C.sIgE-3), and peanut clusters (C.sIgE-2). We then used HC to identify four common ‘sensitisation clusters’ among study participants: (1) multiple sensitisation (sIgE to multiple components across all seven component clusters and singleton components), (2) predominantly dust mite sensitisation (IgE responses mainly to components from C.sIgE-1), (3) predominantly grass and tree sensitisation (sIgE to multiple components across C.sIgE-4–7), and (4) lower-grade sensitisation. We used a bipartite network to explore the relationship between component clusters, sensitisation clusters, and asthma, and the joint density-based nonparametric differential interaction network analysis and classification (JDINAC) to test whether pairwise interactions of component-specific IgEs are associated with asthma. JDINAC with pairwise interactions provided a good balance between sensitivity (0.84) and specificity (0.87), and outperformed penalised logistic regression with individual sIgE components in predicting asthma, with an area under the curve (AUC) of 0.94, compared with 0.73. We then inferred the differential network of pairwise component-specific IgE interactions, which demonstrated that 18 pairs of components predicted asthma. These findings were confirmed in an independent sample of children aged 8 years who participated in the same birth cohort but did not have component-resolved diagnostics (CRD) data at age 11 years. The main limitation of our study was the exclusion of potentially important allergens caused by both the ISAC chip resolution as well as the filtering step. Clustering and the network analyses might have provided different solutions if additional components had been available.

Conclusions

Interactions between pairs of sIgE components are associated with increased risk of asthma and may provide the basis for designing diagnostic tools for asthma.

China may have developed a quantum radar that can spot stealth planes

New Scientist - Ma, 13/11/2018 - 18:00
A defence firm has unveiled a prototype quantum radar. If it works, it could use entangled protons to locate stealth aircraft that normally avoid detection

Mystery “space cow” is a weird new type of powerful space explosion

New Scientist - Ma, 13/11/2018 - 17:15
Months of observations have shown that the strange explosion in space called “the Cow” gets extra power from within, making it a new type of celestial event

Growing demand for oil will lead to shortage and high prices in 2020s

New Scientist - Ma, 13/11/2018 - 01:01
Even if governments step up action on energy, fossil fuel consumption will keep growing for at least another 20 years according to a major new report

An extinct monkey evolved to live like a sloth in the Caribbean

New Scientist - Lu, 12/11/2018 - 21:00
Jamaica was once home to a sloth-like monkey – now we know it was a strange descendant of South America’s titi monkeys that adapted to island life

Earliest known animal might have inflated its body like a balloon

New Scientist - Lu, 12/11/2018 - 17:40
Dickinsonia lived about 560 million years ago and may have been the first animal – but it seems to have inflated its body in a way no animals do today

Pluto’s weird ridges may be glacial landforms unlike any on Earth

New Scientist - Lu, 12/11/2018 - 17:00
Next to Pluto’s heart-shaped plains are strange rolling hills unlike anything we’ve seen on Earth, and they may be left over from receding ancient glaciers

We’ve discovered a whole new defence system against germs in our noses

New Scientist - Lu, 12/11/2018 - 13:00
Billions of tiny sacs filled with weapons and warning signals to other cells are released into the lining of our noses when dangerous bacteria are detected

Monkeys and dogs judge humans by how they treat others

New Scientist - Sa, 10/11/2018 - 11:00
Experiments show that both canines and capuchins prefer those of us who help other people, hinting that morality may have a more-ancient origin than thought

Robots are learning hand gestures by watching hours of TED talks

New Scientist - Sa, 10/11/2018 - 09:00
Hand gestures are difficult for robots to reproduce convincingly, so hundreds of hours of TED videos are being used to teach them how to better gesticulate

Why lichen may be the perfect factories for making rocket fuel on Mars

New Scientist - Sa, 10/11/2018 - 08:00
Lichens can be revived after being subjected to Mars-like conditions, so they could be used on long space flights to produce hydrogen rocket fuel along the way

[Editorial] GBD 2017: a fragile world

The Lancet - Sa, 10/11/2018 - 00:00
Since The Lancet published the first Global Burden of Disease Study (GBD) over 10 years ago, every new iteration has brought improvements in data quality and quantity. With the sharpening of these estimates came a reassuring message: year on year, they portrayed an ever-healthier world. Careful reading of the results of GBD 2017 shatter this comforting trend of gradual improvement and instead show plateauing mortality rates on a background of faltering and uneven progress, era-defining epidemics, and dramatic health worker shortages.

[Global Health Metrics] Global, regional, and national age-sex-specific mortality and life expectancy, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

The Lancet - Sa, 10/11/2018 - 00:00
This analysis of age-sex-specific mortality shows that there are remarkably complex patterns in population mortality across countries. The findings of this study highlight global successes, such as the large decline in under-5 mortality, which reflects significant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, women, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing.

[Global Health Metrics] Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980–2017: a systematic analysis for the Global Burden of Disease Study 2017

The Lancet - Sa, 10/11/2018 - 00:00
Improvements in global health have been unevenly distributed among populations. Deaths due to injuries, substance use disorders, armed conflict and terrorism, neoplasms, and cardiovascular disease are expanding threats to global health. For causes of death such as lower respiratory and enteric infections, more rapid progress occurred for children than for the oldest adults, and there is continuing disparity in mortality rates by sex across age groups. Reductions in the death rate of some common diseases are themselves slowing or have ceased, primarily for NCDs, and the death rate for selected causes has increased in the past decade.

[Global Health Metrics] Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

The Lancet - Sa, 10/11/2018 - 00:00
Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss.

[Global Health Metrics] Global, regional, and national disability-adjusted life-years (DALYs) for 359 diseases and injuries and healthy life expectancy (HALE) for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Dis

The Lancet - Sa, 10/11/2018 - 00:00
With increasing life expectancy in most countries, the question of whether the additional years of life gained are spent in good health or poor health has been increasingly relevant because of the potential policy implications, such as health-care provisions and extending retirement ages. In some locations, a large proportion of those additional years are spent in poor health. Large inequalities in HALE and disease burden exist across countries in different SDI quintiles and between sexes. The burden of disabling conditions has serious implications for health system planning and health-related expenditures.
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