Riviste scientifiche

Snowglow can cause the night sky to be twice as bright as a full moon

New Scientist - Me, 07/08/2019 - 12:07
A combination of snow and cloud cover can make light pollution in the sky over 180 times brighter, potentially affecting the sleep cycles of nocturnal animals

Have we found the true cause of diabetes, stroke and Alzheimer's?

New Scientist - Me, 07/08/2019 - 07:00
The diseases most people die of have been attributed to unhealthy lifestyles. But evidence now suggests bacteria are to blame, heralding a revolution in medicine

Staring down seagulls can stop them stealing your chips

New Scientist - Me, 07/08/2019 - 01:01
In experiments conducted in UK seaside towns, only 26 per cent of herring gulls tried to steal chips when they were being watched

World’s largest parrot was a metre tall and lived 19 million years ago

New Scientist - Me, 07/08/2019 - 01:01
Palaeontologists working in New Zealand have discovered the first evidence of giant parrots, which they believe weighed 7 kilograms and lived 19 million years ago

Pregnancy after bariatric surgery and adverse perinatal outcomes: A systematic review and meta-analysis

PLoS Medicine - Ma, 06/08/2019 - 23:00

by Zainab Akhter, Judith Rankin, Dries Ceulemans, Lem Ngongalah, Roger Ackroyd, Roland Devlieger, Rute Vieira, Nicola Heslehurst

Background

Women who undergo bariatric surgery prior to pregnancy are less likely to experience comorbidities associated with obesity such as gestational diabetes and hypertension. However, bariatric surgery, particularly malabsorptive procedures, can make patients susceptible to deficiencies in nutrients that are essential for healthy fetal development. The objective of this systematic review and meta-analysis is to investigate the association between pregnancy after bariatric surgery and adverse perinatal outcomes.

Methods and findings

Searches were conducted in Medline, Embase, PsycINFO, CINAHL, Scopus, and Google Scholar from inception to June 2019, supplemented by hand-searching reference lists, citations, and journals. Observational studies comparing perinatal outcomes post-bariatric surgery to pregnancies without prior bariatric surgery were included. Outcomes of interest were perinatal mortality, congenital anomalies, preterm birth, postterm birth, small and large for gestational age (SGA/LGA), and neonatal intensive care unit (NICU) admission. Pooled effect sizes were calculated using random-effects meta-analysis. Where data were available, results were subgrouped by type of bariatric surgery. We included 33 studies with 14,880 pregnancies post-bariatric surgery and 3,979,978 controls. Odds ratios (ORs) were increased after bariatric surgery (all types combined) for perinatal mortality (1.38, 95% confidence interval [CI] 1.03–1.85, p = 0.031), congenital anomalies (1.29, 95% CI 1.04–1.59, p = 0.019), preterm birth (1.57, 95% CI 1.38–1.79, p < 0.001), and NICU admission (1.41, 95% CI 1.25–1.59, p < 0.001). Postterm birth decreased after bariatric surgery (OR 0.46, 95% CI 0.35–0.60, p < 0.001). ORs for SGA increased (2.72, 95% CI 2.32–3.20, p < 0.001) and LGA decreased (0.24, 95% CI 0.14–0.41, p < 0.001) after gastric bypass but not after gastric banding. Babies born after bariatric surgery (all types combined) weighed over 200 g less than those born to mothers without prior bariatric surgery (weighted mean difference −242.42 g, 95% CI −307.43 to −177.40 g, p < 0.001). There was low heterogeneity for all outcomes (I2 < 40%) except LGA. Limitations of our study are that as a meta-analysis of existing studies, the results are limited by the quality of the included studies and available data, unmeasured confounders, and the small number of studies for some outcomes.

Conclusions

In our systematic review of observational studies, we found that bariatric surgery, especially gastric bypass, prior to pregnancy was associated with increased risk of some adverse perinatal outcomes. This suggests that women who have undergone bariatric surgery may benefit from specific preconception and pregnancy nutritional support and increased monitoring of fetal growth and development. Future studies should explore whether restrictive surgery results in better perinatal outcomes, compared to malabsorptive surgery, without compromising maternal outcomes. If so, these may be the preferred surgery for women of reproductive age.

Trial registration

PROSPERO CRD42017051537.

Impact of nutritional supplementation during pregnancy on antibody responses to diphtheria-tetanus-pertussis vaccination in infants: A randomised trial in The Gambia

PLoS Medicine - Ma, 06/08/2019 - 23:00

by Sandra G. Okala, Momodou K. Darboe, Fatou Sosseh, Bakary Sonko, Tisbeh Faye-Joof, Andrew M. Prentice, Sophie E. Moore

Background

Exposure to a nutritionally deficient environment during fetal life and early infancy may adversely alter the ontogeny of the immune system and affect an infant’s ability to mount an optimal immune response to vaccination. We examined the effects of maternal nutritional supplementation during pregnancy on infants’ antibody responses to the diphtheria-tetanus-pertussis (DTP) vaccine included in the Expanded Programme on Immunisation (EPI).

Methods and findings

The Early Nutrition and Immune Development (ENID) trial was a randomised, partially blinded trial conducted between April 2010 and February 2015 in the rural West Kiang region of The Gambia, a resource-poor region affected by chronic undernutrition. Pregnant women (<20 weeks’ gestation) with a singleton pregnancy (n = 875) were randomised to receive one of four supplements: iron-folic acid (FeFol; standard of care), multiple micronutrient (MMN), protein-energy (PE), or PE + MMN daily from enrolment (mean [SD] 13.7 [3.3] weeks’ gestation) until delivery. Infants were administered the DTP vaccine at 8, 12, and 16 weeks of age according to the Gambian Government protocol. Results for the primary outcome of the trial (infant thymic size) were described previously; here, we report on a secondary outcome, infant antibody response to vaccination. The effects of supplementation on mean DTP antibody titres measured in blood samples collected from infants at 12 weeks (n = 710) and 24 weeks (n = 662) were analysed with adjustment for confounders including maternal age, compliance to supplement, and infant sex and season. At 12 weeks, following a single dose of the vaccine, compared with FeFol (mean 95% confidence interval [CI]; 0.11 IU/mL, 0.09–0.12), antenatal supplementation with MMN or MMN + PE resulted in 42.4% (95% CI 20.1–64.6; p < 0.001) and 29.4% (6.4–52.5; p = 0.012) higher mean anti-diphtheria titres, respectively. Mean anti-tetanus titres were higher by 9.0% (5.5–12.5), 7.8% (4.3–11.4), and 7.3% (4.0–10.7) in MMN, PE, and PE + MMN groups (all, p < 0.001), respectively, than in the FeFol group (0.55 IU/mL, 0.52–0.58). Mean anti-pertussis titres were not significantly different in the FeFol, MMN, and PE + MNN groups but were all higher than in the PE group (all, p < 0.001). At 24 weeks, following all three doses, no significant differences in mean anti-diphtheria titres were detected across the supplement groups. Mean anti-tetanus titres were 3.4% (0.19–6.5; p = 0.038) higher in the PE + MMN group than in the FeFol group (3.47 IU/mL, 3.29–3.66). Mean anti-pertussis titres were higher by 9.4% (3.3–15.5; p = 0.004) and 15.4% (9.6–21.2; p < 0.001) in PE and PE + MMN groups, compared with the FeFol group (74.9 IU/mL, 67.8–82.8). Limitations of the study included the lack of maternal antibody status (breast milk or plasma) or prevaccination antibody measurements in the infants.

Conclusion

According to our results from rural Gambia, maternal supplementation with MMN combined with PE during pregnancy enhanced antibody responses to the DTP vaccine in early infancy. Provision of nutritional supplements to pregnant women in food insecure settings may improve infant immune development and responses to EPI vaccines.

Trial registration

ISRCTN49285450.

Neonatal, infant, and childhood growth following metformin versus insulin treatment for gestational diabetes: A systematic review and meta-analysis

PLoS Medicine - Ma, 06/08/2019 - 23:00

by Jane L. Tarry-Adkins, Catherine E. Aiken, Susan E. Ozanne

Background

Metformin is increasingly offered as an acceptable and economic alternative to insulin for treatment of gestational diabetes mellitus (GDM) in many countries. However, the impact of maternal metformin treatment on the trajectory of fetal, infant, and childhood growth is unknown.

Methods and findings

PubMed, Ovid Embase, Medline, Web of Science, ClinicalTrials.gov, and the Cochrane database were systematically searched (from database inception to 26 February 2019). Outcomes of GDM-affected pregnancies randomised to treatment with metformin versus insulin were included (randomised controlled trials and prospective randomised controlled studies) from cohorts including European, American, Asian, Australian, and African women. Studies including pregnant women with pre-existing diabetes or non-diabetic women were excluded, as were trials comparing metformin treatment with oral glucose-lowering agents other than insulin. Two reviewers independently assessed articles for eligibility and risk of bias, and conflicts were resolved by a third reviewer. Outcome measures were parameters of fetal, infant, and childhood growth, including weight, height, BMI, and body composition. In total, 28 studies (n = 3,976 participants) met eligibility criteria and were included in the meta-analysis. No studies reported fetal growth parameters; 19 studies (n = 3,723 neonates) reported measures of neonatal growth. Neonates born to metformin-treated mothers had lower birth weights (mean difference −107.7 g, 95% CI −182.3 to −32.7, I2 = 83%, p = 0.005) and lower ponderal indices (mean difference −0.13 kg/m3, 95% CI −0.26 to 0.00, I2 = 0%, p = 0.04) than neonates of insulin-treated mothers. The odds of macrosomia (odds ratio [OR] 0.59, 95% CI 0.46 to 0.77, p < 0.001) and large for gestational age (OR 0.78, 95% CI 0.62 to 0.99, p = 0.04) were lower following maternal treatment with metformin compared to insulin. There was no difference in neonatal height or incidence of small for gestational age between groups. Two studies (n = 411 infants) reported measures of infant growth (18–24 months of age). In contrast to the neonatal phase, metformin-exposed infants were significantly heavier than those in the insulin-exposed group (mean difference 440 g, 95% CI 50 to 830, I2 = 4%, p = 0.03). Three studies (n = 520 children) reported mid-childhood growth parameters (5–9 years). In mid-childhood, BMI was significantly higher (mean difference 0.78 kg/m2, 95% CI 0.23 to 1.33, I2 = 7%, p = 0.005) following metformin exposure than following insulin exposure, although the difference in absolute weights between the groups was not significantly different (p = 0.09). Limited evidence (1 study with data treated as 2 cohorts) suggested that adiposity indices (abdominal [p = 0.02] and visceral [p = 0.03] fat volumes) may be higher in children born to metformin-treated compared to insulin-treated mothers. Study limitations include heterogeneity in metformin dosing, heterogeneity in diagnostic criteria for GDM, and the scarcity of reporting of childhood outcomes.

Conclusions

Following intrauterine exposure to metformin for treatment of maternal GDM, neonates are significantly smaller than neonates whose mothers were treated with insulin during pregnancy. Despite lower average birth weight, metformin-exposed children appear to experience accelerated postnatal growth, resulting in heavier infants and higher BMI by mid-childhood compared to children whose mothers were treated with insulin. Such patterns of low birth weight and postnatal catch-up growth have been reported to be associated with adverse long-term cardio-metabolic outcomes. This suggests a need for further studies examining longitudinal perinatal and childhood outcomes following intrauterine metformin exposure. This review protocol was registered with PROSPERO under registration number CRD42018117503.

Physicists who came up with supergravity win $3m Breakthrough Prize

New Scientist - Ma, 06/08/2019 - 16:00
Supergravity is an idea that could unite general relativity with quantum mechanics, and the three physicists who formulated it have now won a $3 million prize for their work

We could use Earth's atmosphere as a giant lens for a space telescope

New Scientist - Ma, 06/08/2019 - 14:13
A space telescope could use the whole Earth as a lens by capturing light deflected off the atmosphere to help us search for signs of life on exoplanets

Artificial tongue could taste whisky to make sure it isn't counterfeit

New Scientist - Ma, 06/08/2019 - 01:01
An artificial tongue can taste subtle differences between drams of whisky and could one day help tackle the counterfeit alcohol trade

[Series] Genomic medicine for undiagnosed diseases

The Lancet - Ma, 06/08/2019 - 00:30
One of the primary goals of genomic medicine is to improve diagnosis through identification of genomic conditions, which could improve clinical management, prevent complications, and promote health. We explore how genomic medicine is being used to obtain molecular diagnoses for patients with previously undiagnosed diseases in prenatal, paediatric, and adult clinical settings. We focus on the role of clinical genomic sequencing (exome and genome) in aiding patients with conditions that are undiagnosed even after extensive clinical evaluation and testing.

[Series] Family health history: underused for actionable risk assessment

The Lancet - Ma, 06/08/2019 - 00:30
Family health history (FHH) is the most useful means of assessing risk for common chronic diseases. The odds ratio for risk of developing disease with a positive FHH is frequently greater than 2, and actions can be taken to mitigate risk by adhering to screening guidelines, genetic counselling, genetic risk testing, and other screening methods. Challenges to the routine acquisition of FHH include constraints on provider time to collect data and the difficulty in accessing risk calculators. Disease-specific and broader risk assessment software platforms have been developed, many with clinical decision support and informatics interoperability, but few access patient information directly.

[Comment] Genomic medicine: time for health-care transformation

The Lancet - Ma, 06/08/2019 - 00:30
Genomic medicine—the use of genetic information to inform medical care or predict risk of disease—is beginning to transform health care. The first human genome cost about US$3 billion to sequence.1,2 A whole human genome can now be sequenced for under $1000, and for even less it is possible to read targeted parts of the genome (panels) or the protein coding part (the exome). The timely and comprehensive Lancet Series on genomic medicine3–7 reviews the opportunities, challenges, resources, and techniques for application of next generation sequencing in health care.

[Series] Pharmacogenomics

The Lancet - Ma, 06/08/2019 - 00:30
Genomic medicine, which uses DNA variation to individualise and improve human health, is the subject of this Series of papers. The idea that genetic variation can be used to individualise drug therapy—the topic addressed here—is often viewed as within reach for genomic medicine. We have reviewed general mechanisms underlying variability in drug action, the role of genetic variation in mediating beneficial and adverse effects through variable drug concentrations (pharmacokinetics) and drug actions (pharmacodynamics), available data from clinical trials, and ongoing efforts to implement pharmacogenetics in clinical practice.

[Series] Building evidence and measuring clinical outcomes for genomic medicine

The Lancet - Ma, 06/08/2019 - 00:30
Human genomic sequencing has potential diagnostic, prognostic, and therapeutic value across a wide breadth of clinical disciplines. One barrier to widespread adoption is the paucity of evidence for improved outcomes in patients who do not already have an indication for more focused testing. In this Series paper, we review clinical outcome studies in genomic medicine and discuss the important features and key challenges to building evidence for next generation sequencing in the context of routine patient care.

[Perspectives] Teri Manolio: steering genomics into clinical medicine

The Lancet - Ma, 06/08/2019 - 00:30
After almost three decades of research in genomics, Teri Manolio, Director of Genomic Medicine at the National Human Genome Research Institute (NHGRI), Bethesda, MD, USA, believes we have reached a key moment when genomics is beginning to have an impact in clinical medicine. “The area of pharmacogenomics is a good example of clinical applicability as we can help guide clinical decision making according to drug reactions that are genetically mediated”, she says. Manolio, who is a lead author of a new Lancet genomic medicine Series, sees the emerging role of genomics in clinical medicine as a natural progression in aiding clinical decision making.

[Series] Opportunities, resources, and techniques for implementing genomics in clinical care

The Lancet - Ma, 06/08/2019 - 00:30
Advances in technologies for assessing genomic variation and an increasing understanding of the effects of genomic variants on health and disease are driving the transition of genomics from the research laboratory into clinical care. Genomic medicine, or the use of an individual's genomic information as part of their clinical care, is increasingly gaining acceptance in routine practice, including in assessing disease risk in individuals and their families, diagnosing rare and undiagnosed diseases, and improving drug safety and efficacy.

Most people would rather lose their job to a robot than another human

New Scientist - Lu, 05/08/2019 - 17:00
Most people would prefer a robot to take their job if they had to lose it, but they would prefer to see another human step in if a co-worker was going to lose theirs

Space agency chief fired after revealing recent Amazon deforestation

New Scientist - Lu, 05/08/2019 - 16:33
Brazil’s president Jair Bolsonaro has fired the director of the agency that monitors deforestation in the Amazon after it revealed a big increase in deforestation

Two planets orbiting a nearby star could have oceans and maybe life

New Scientist - Do, 04/08/2019 - 09:00
Teegarden’s star, 12.5 light years away, is orbited by two planets, and even if they have very thin atmospheres they may be able to maintain liquid oceans
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