Mapping anorexia nervosa genes to clinical phenotypes

BACKGROUND

Anorexia nervosa (AN) is a psychiatric disorder with complex etiology, with a significant portion of disease risk imparted by genetics. Traditional genome-wide association studies (GWAS) produce principal evidence for the association of genetic variants with disease. Transcriptomic imputation (TI) allows for the translation of those variants into regulatory mechanisms, which can then be used to assess the functional outcome of genetically regulated gene expression (GReX) in a broader setting through the use of phenome-wide association studies (pheWASs) in large and diverse clinical biobank populations with electronic health record phenotypes.

METHODS

Here, we applied TI using S-PrediXcan to translate the most recent PGC-ED AN GWAS findings into AN-GReX. For significant genes, we imputed AN-GReX in the Mount Sinai BioMe™ Biobank and performed pheWASs on over 2000 outcomes to test the clinical consequences of aberrant expression of these genes. We performed a secondary analysis to assess the impact of body mass index (BMI) and sex on AN-GReX clinical associations.

RESULTS

Our S-PrediXcan analysis identified 53 genes associated with AN, including what is, to our knowledge, the first-genetic association of AN with the major histocompatibility complex. AN-GReX was associated with autoimmune, metabolic, and gastrointestinal diagnoses in our biobank cohort, as well as measures of cholesterol, medications, substance use, and pain. Additionally, our analyses showed moderation of AN-GReX associations with measures of cholesterol and substance use by BMI, and moderation of AN-GReX associations with celiac disease by sex.

CONCLUSIONS

Our BMI-stratified results provide potential avenues of functional mechanism for AN-genes to investigate further.

Bioactive adrenomedullin a prognostic biomarker in patients with mild to moderate dyspnea at the emergency department: an observational study

Acute dyspnea with underlying congestion is a leading cause of emergency department (ED) visits with high rates of hospitalization. Adrenomedullin is a vasoactive neuropeptide hormone secreted by the endothelium that mediates vasodilation and maintains vascular integrity. Plasma levels of biologically active adrenomedullin (bio-ADM) predict septic shock and vasopressor need in critically ill patients and are associated with congestion in patients with acute heart failure (HF) but the prognostic value in unselected dyspneic patients at the ED is unknown. The purpose of this study is to test if bio-ADM predicts adverse outcomes when sampled in patients with acute dyspnea at presentation to the ED. In this single-center prospective observational study, we included 1402 patients from the ADYS (Acute DYSpnea at the Emergency Department) cohort in Malmö, Sweden. We fitted logistic regression models adjusted for sex, age, N-terminal pro-B-type natriuretic peptide (NT-proBNP), creatinine, and C-reactive protein (CRP) to associate bio-ADM plasma levels to mortality, hospitalization, intravenous (IV) diuretic treatment and HF diagnosis. Using receiver operating characteristic (ROC) curve analysis we evaluated bio-ADM discrimination for these outcomes compared to a reference model (sex, age, NT-proBNP, creatinine, and CRP). Model performance was compared by performing a likelihood ratio test on the deviances of the models. Bio-ADM (per interquartile range from median) predicts both 90-day mortality [odds ratio (OR): 1.5, 95% confidence interval (CI) 1.2-2.0, p < 0.002] and hospitalization (OR: 1.5, 95% CI 1.2-1.8, p < 0.001) independently of sex, age, NT-proBNP, creatinine, and CRP. Bio-ADM statistically significantly improves the reference model in predicting mortality (added χ² 9.8, p = 0.002) and hospitalization (added χ² 14.1, p = 0.0002), and is associated with IV diuretic treatment and HF diagnosis at discharge. Plasma levels of bio-ADM sampled at ED presentation in acutely dyspneic patients are independently associated with 90-day mortality, hospitalization and indicate the need for decongestive therapy.

Transforming environmental governance: critical action intellectuals and their praxis in the field

Over the past decade, widespread concern has emerged over how environmental governance can be transformed to avoid impending catastrophes such as climate change, biodiversity loss, and livelihood insecurity. A variety of approaches have emerged, focusing on either politics, technological breakthrough, social movements, or macro-economic processes as the main drivers of change. In contrast, this paper presents theoretical insights about how systemic change in environmental governance can be triggered by critical and intellectually grounded social actors in specific contexts of environment and development. Conceptualising such actors as critical action intellectuals (CAI), we analyze how CAI emerge in specific socio-environmental contexts and contribute to systemic change in governance. CAI trigger transformative change by shifting policy discourse, generating alternative evidence, and challenging dominant policy assumptions, whilst aiming to empower marginalized groups. While CAI do not work in a vacuum, nor are the sole force in transformation, we nevertheless show that the praxis of CAI within fields of environmental governance has the potential to trigger transformation. We illustrate this through three cases of natural resource governance in Nepal, Nicaragua and Guatemala, and Kenya, where the authors themselves have engaged as CAI. We contribute to theorising the 'how' of transformation by showing the ways CAI praxis reshape fields of governance and catalyze transformation, distinct from, and at times complementary to, other dominant drivers such as social movements, macroeconomic processes or technological breakthroughs.

Associations of pre-pandemic levels of physical function and physical activity with COVID-19-like symptoms during the outbreak

Background

One’s physical function and physical activity levels can predispose or protect from the development of respiratory infections. We aimed to explore the associations between pre-pandemic levels of physical function and physical activity and the development of COVID-19-like symptoms in Swedish older adults.

Methods

We analyzed data from 904 individuals aged ≥ 68 years from the population-based Swedish National study on Aging and Care in Kungsholmen. COVID-19-like symptoms were assessed by phone interview (March–June 2020) and included fever, cough, sore throat and/or a cold, headache, pain in muscles, legs and joints, loss of taste and/or odor, breathing difficulties, chest pain, gastrointestinal symptoms, and eye inflammation. Muscle strength, mobility, and physical activity were examined in 2016–2018 by objective testing. Data were analyzed using logistic regression models in the total sample and stratifying by age.

Results

During the first outbreak of the pandemic, 325 (36%) individuals from our sample developed COVID-19-like symptoms. Those with slower performance in the chair stand test had an odds ratio (OR) of 1.5 (95% confidence interval [CI] 1.1–2.1) for presenting with COVID-19-like symptoms compared to better performers, after adjusting for potential confounders. The association was even higher among people aged ≥ 80 years (OR 2.6; 95% CI 1.5–4.7). No significant associations were found between walking speed or engagement in moderate-to-vigorous physical activity and the likelihood to develop COVID-19-like symptoms.

Conclusion

Poor muscle strength, a possible indicator of frailty, may predispose older adults to higher odds of developing COVID-19-like symptoms, especially among the oldest-old.

The Sociability Argument for the Burqa Ban: A Qualified Defence

Over the past decade, countries such as France, Belgium, Denmark, Austria, Latvia, and Bulgaria have banned face-coverings from public spaces. These bans are popularly known as 'burqa bans' as they seem to have been drafted with the aim of preventing people from wearing burqas and niqabs specifically. The scholarly response to these bans has been overwhelmingly negative, with several lawyers and philosophers arguing that they violate the human right to freedom of religion. While this article shares some of the concerns that have been raised, it argues that banning face-coverings in public is morally justified under certain conditions with the exception of facemasks that are necessary for the containment of infectious diseases, such as COVID-19. The reason for this is that those who publicly cover their face make it very difficult for other members of society to socially interact with them, especially for those who are deaf or hard-of-hearing, which is problematic in an age where many people are chronically lonely or at risk of becoming chronically lonely. As such, this article can be understood as a more elaborate, and arguably more sophisticated, defence of the justification that France offered for its face-covering ban before the European Court of Human Rights, namely that covering one's face undermines the conditions for 'living together'.

Catastrophic expenditure and impoverishment after caesarean section in Sierra Leone: An evaluation of the free health care initiative

BACKGROUND

Utilizing surgical services, including caesarean sections, can result in catastrophic expenditure and impoverishment. In 2010, Sierra Leone introduced the Free Health Care Initiative (FHCI), a national financial risk protection program for the most vulnerable groups. Aim of this study was to investigate catastrophic expenditure and impoverishment related to caesarean section in Sierra Leone and evaluate the impact of the FHCI.

METHODS

Women who delivered by caesarean section in nine hospitals were followed up with home visits one month after surgery, and data on medical and non-medical expenditures were collected. Individual income was estimated based on household characteristics and used to determine catastrophic expenditure and impoverishment for each patient. The impact of the FHCI was assessed by comparing actual expenditure with counterfactual expenditures had the initiative not existed.

RESULTS

For the 1146 patients in the study, the median expenditure was 23 (IQR 4; 56) international dollars (Int$). Patients in the poorest quintile spent a median Int$ 59 (IQR 28; 76), which was significantly more than patients in the richest quintile, who spent a median Int$ 17 (IQR 2; 38, p<0.001). Travel (32.9%) and food (28.7%) were the two largest expenses. Catastrophic expenditure was encountered by 12.0% and 4.0% (10% and 25% threshold, respectively) of the women. Without the FHCI, 66.1% and 28.8% of the women would have encountered catastrophic expenditure.

CONCLUSION

Many women in Sierra Leone face catastrophic expenditure related to caesarean section, mainly through food and travel expenses, and the poor are disproportionally affected. The FHCI is effective in reducing the risk of catastrophic expenditure related to caesarean section, but many patients are still exposed to financial hardship, suggesting that additional support is needed for Sierra Leone's poorest patients.

Exploring functionality of the reverse β-oxidation pathway in Corynebacterium glutamicum for production of adipic acid

BACKGROUND

Adipic acid, a six-carbon platform chemical mainly used in nylon production, can be produced via reverse β-oxidation in microbial systems. The advantages posed by Corynebacterium glutamicum as a model cell factory for implementing the pathway include: (1) availability of genetic tools, (2) excretion of succinate and acetate when the TCA cycle becomes overflown, (3) initiation of biosynthesis with succinyl-CoA and acetyl-CoA, and (4) established succinic acid production. Here, we implemented the reverse β-oxidation pathway in C. glutamicum and assessed its functionality for adipic acid biosynthesis.

RESULTS

To obtain a non-decarboxylative condensation product of acetyl-CoA and succinyl-CoA, and to subsequently remove CoA from the condensation product, we introduced heterologous 3-oxoadipyl-CoA thiolase and acyl-CoA thioesterase into C. glutamicum. No 3-oxoadipic acid could be detected in the cultivation broth, possibly due to its endogenous catabolism. To successfully biosynthesize and secrete 3-hydroxyadipic acid, 3-hydroxyadipyl-CoA dehydrogenase was introduced. Addition of 2,3-dehydroadipyl-CoA hydratase led to biosynthesis and excretion of trans-2-hexenedioic acid. Finally, trans-2-enoyl-CoA reductase was inserted to yield 37 µg/L of adipic acid.

CONCLUSIONS

In the present study, we engineered the reverse β-oxidation pathway in C. glutamicum and assessed its potential for producing adipic acid from glucose as starting material. The presence of adipic acid, albeit small amount, in the cultivation broth indicated that the synthetic genes were expressed and functional. Moreover, 2,3-dehydroadipyl-CoA hydratase and β-ketoadipyl-CoA thiolase were determined as potential target for further improvement of the pathway.

A simple cognitive task intervention to prevent intrusive memories after trauma in patients in the Emergency Department: A randomized controlled trial terminated due to COVID-19

OBJECTIVE

This randomised controlled trial (RCT) aimed to investigate the effects of a simple cognitive task intervention on intrusive memories ("flashbacks") and associated symptoms following a traumatic event. Patients presenting to a Swedish emergency department (ED) soon after a traumatic event were randomly allocated (1:1) to the simple cognitive task intervention (memory cue + mental rotation instructions + computer game "Tetris" for at least 20 min) or control (podcast, similar time). We planned follow-ups at one-week, 1-month, and where possible, 3- and 6-months post-trauma. Anticipated enrolment was N = 148.

RESULTS

The RCT was terminated prematurely after recruiting N = 16 participants. The COVID-19 pandemic prevented recruitment/testing in the ED because: (i) the study required face-to-face contact between participants, psychology researchers, ED staff, and patients, incurring risk of virus transmission; (ii) the host ED site received COVID-19 patients; and (iii) reduced flow of patients otherwise presenting to the ED in non-pandemic conditions (e.g. after trauma). We report on delivery of study procedures, recruitment, treatment adherence, outcome completion (primary outcome: number of intrusive memories during week 5), attrition, and limitations. The information presented and limitations may enable our group and others to learn from this terminated study. Trial registration ClinicalTrials.gov: NCT04185155 (04-12-2019).

Transcriptional bursts explain autosomal random monoallelic expression and affect allelic imbalance

Transcriptional bursts render substantial biological noise in cellular transcriptomes. Here, we investigated the theoretical extent of allelic expression resulting from transcriptional bursting and how it compared to the amount biallelic, monoallelic and allele-biased expression observed in single-cell RNA-sequencing (scRNA-seq) data. We found that transcriptional bursting can explain the allelic expression patterns observed in single cells, including the frequent observations of autosomal monoallelic gene expression. Importantly, we identified that the burst frequency largely determined the fraction of cells with monoallelic expression, whereas the burst size had little effect on monoallelic observations. The high consistency between the bursting model predictions and scRNA-seq observations made it possible to assess the heterogeneity of a group of cells as their deviation in allelic observations from the expected. Finally, both burst frequency and size contributed to allelic imbalance observations and reinforced that studies of allelic imbalance can be confounded from the inherent noise in transcriptional bursting. Altogether, we demonstrate that allele-level transcriptional bursting renders widespread, although predictable, amounts of monoallelic and biallelic expression in single cells and cell populations.

Genes are transcribed into RNA and further translated into proteins. The maternal and paternal copy of each gene are typically transcribed independently, and transcription itself occur in discrete stochastic bursts (transcriptional bursts). Pioneering single-cell analysis of RNA across cells revealed abundant fluctuations in the amounts of maternal and paternal RNA in cells, with frequent observations of RNA from only the maternal or paternal gene copy (monoallelic expression). In this study, we investigated to which extent the observed monoallelic expression across single cells can be explained by transcriptional bursting. We demonstrate that the process of transcriptional bursting is sufficient to explain the amount of monoallelic expression, and we further demonstrate that the frequency of bursts mainly determines the frequency of monoallelic observations. Furthermore, we show that transcriptional bursts may lead to false positive observations of monoallelic expression across cell populations. Therefore, stochastic transcription renders large fluctuations in allelic origin of RNA in cells over time, including frequent monoallelic observations when profiling single cells.

R.ROSETTA: an interpretable machine learning framework

BACKGROUND

Machine learning involves strategies and algorithms that may assist bioinformatics analyses in terms of data mining and knowledge discovery. In several applications, viz. in Life Sciences, it is often more important to understand how a prediction was obtained rather than knowing what prediction was made. To this end so-called interpretable machine learning has been recently advocated. In this study, we implemented an interpretable machine learning package based on the rough set theory. An important aim of our work was provision of statistical properties of the models and their components.

RESULTS

We present the R.ROSETTA package, which is an R wrapper of ROSETTA framework. The original ROSETTA functions have been improved and adapted to the R programming environment. The package allows for building and analyzing non-linear interpretable machine learning models. R.ROSETTA gathers combinatorial statistics via rule-based modelling for accessible and transparent results, well-suited for adoption within the greater scientific community. The package also provides statistics and visualization tools that facilitate minimization of analysis bias and noise. The R.ROSETTA package is freely available at https://github.com/komorowskilab/R.ROSETTA . To illustrate the usage of the package, we applied it to a transcriptome dataset from an autism case-control study. Our tool provided hypotheses for potential co-predictive mechanisms among features that discerned phenotype classes. These co-predictors represented neurodevelopmental and autism-related genes.

CONCLUSIONS

R.ROSETTA provides new insights for interpretable machine learning analyses and knowledge-based systems. We demonstrated that our package facilitated detection of dependencies for autism-related genes. Although the sample application of R.ROSETTA illustrates transcriptome data analysis, the package can be used to analyze any data organized in decision tables.

Functional vitamin K insufficiency, vascular calcification and mortality in advanced chronic kidney disease: A cohort study

Patients with chronic kidney disease (CKD) suffer from vitamin K deficiency and are at high risk of vascular calcification (VC) and premature death. We investigated the association of functional vitamin K deficiency with all-cause mortality and whether this association is modified by the presence of VC in CKD stage 5 (CKD G5). Plasma dephosphorylated-uncarboxylated matrix Gla-protein (dp-ucMGP), a circulating marker of functional vitamin K deficiency, and other laboratory and clinical data were determined in 493 CKD G5 patients. VC was assessed in subgroups by Agatston scoring of coronary artery calcium (CAC) and aortic valve calcium (AVC). Backward stepwise regression did not identify dp-ucMGP as an independent determinant of VC. During a median follow-up of 42 months, 93 patients died. Each one standard deviation increment in dp-ucMGP was associated with increased risk of all-cause mortality (sub-hazard ratio (sHR) 1.17; 95% confidence interval, 1.01-1.37) adjusted for age, sex, cardiovascular disease, diabetes, body mass index, inflammation, and dialysis treatment. The association remained significant when further adjusted for CAC and AVC in sub-analyses (sHR 1.22, 1.01-1.48 and 1.27, 1.01-1.60, respectively). In conclusion, functional vitamin K deficiency associates with increased mortality risk that is independent of the presence of VC in patients with CKD G5.

Differences in structure and hibernation mechanism highlight diversification of the microsporidian ribosome

Assembling and powering ribosomes are energy-intensive processes requiring fine-tuned cellular control mechanisms. In organisms operating under strict nutrient limitations, such as pathogenic microsporidia, conservation of energy via ribosomal hibernation and recycling is critical. The mechanisms by which hibernation is achieved in microsporidia, however, remain poorly understood. Here, we present the cryo–electron microscopy structure of the ribosome from Paranosema locustae spores, bound by the conserved eukaryotic hibernation and recycling factor Lso2. The microsporidian Lso2 homolog adopts a V-shaped conformation to bridge the mRNA decoding site and the large subunit tRNA binding sites, providing a reversible ribosome inactivation mechanism. Although microsporidian ribosomes are highly compacted, the P. locustae ribosome retains several rRNA segments absent in other microsporidia, and represents an intermediate state of rRNA reduction. In one case, the near complete reduction of an expansion segment has resulted in a single bound nucleotide, which may act as an architectural co-factor to stabilize a protein–protein interface. The presented structure highlights the reductive evolution in these emerging pathogens and sheds light on a conserved mechanism for eukaryotic ribosome hibernation.

Tiny pathogenic eukaryotes called microsporidia have evolved highly compact ribosomes, smaller than bacterial ribosomes, and employ diverse hibernation factors to facilitate ribosome inactivation and recovery from the latent spore stage, including the conserved eukaryotic hibernation and recycling factor Lso2.

Inferring transmission heterogeneity using virus genealogies: Estimation and targeted prevention

Spread of HIV typically involves uneven transmission patterns where some individuals spread to a large number of individuals while others to only a few or none. Such transmission heterogeneity can impact how fast and how much an epidemic spreads. Further, more efficient interventions may be achieved by taking such transmission heterogeneity into account. To address these issues, we developed two phylogenetic methods based on virus sequence data: 1) to generally detect if significant transmission heterogeneity is present, and 2) to pinpoint where in a phylogeny high-level spread is occurring. We derive inference procedures to estimate model parameters, including the amount of transmission heterogeneity, in a sampled epidemic. We show that it is possible to detect transmission heterogeneity under a wide range of simulated situations, including incomplete sampling, varying levels of heterogeneity, and including within-host genetic diversity. When evaluating real HIV-1 data from different epidemic scenarios, we found a lower level of transmission heterogeneity in slowly spreading situations and a higher level of heterogeneity in data that included a rapid outbreak, while R0 and Sackin's index (overall tree shape statistic) were similar in the two scenarios, suggesting that our new method is able to detect transmission heterogeneity in real data. We then show by simulations that targeted prevention, where we pinpoint high-level spread using a coalescence measurement, is efficient when sequence data are collected in an ongoing surveillance system. Such phylogeny-guided prevention is efficient under both single-step contact tracing as well as iterative contact tracing as compared to random intervention.

A functional observational battery for evaluation of neurological outcomes in a rat model of acute bacterial meningitis

BACKGROUND

Acute bacterial meningitis is a disease with a high mortality and a high incidence of neurological sequelae in survivors. There is an acute need to develop new adjuvant therapies. To ensure that new therapies evaluated in animal models are translatable to humans, studies must evaluate clinically relevant and patient-important outcomes, including neurological symptoms and sequelae.

METHODS

We developed and tested a functional observational battery to quantify the severity of a variety of relevant neurological and clinical symptoms in a rat model of bacterial meningitis. The functional observational battery included symptoms relating to general clinical signs, gait and posture abnormalities, involuntary motor movements, focal neurological signs, and neuromotor abnormalities which were scored according to severity and summed to obtain a combined clinical and neurological score. To test the functional observational battery, adult Sprague-Dawley rats were infected by intracisternal injection of a clinical isolate of Streptococcus pneumoniae. Rats were evaluated for 6 days following the infection.

RESULTS

Pneumococcal meningitis was not lethal in this model; however, it induced severe neurological symptoms. Most common symptoms were hearing loss (75% of infected vs 0% of control rats; p = 0.0003), involuntary motor movements (75% of infected vs 0% of control rats; p = 0.0003), and gait and posture abnormality (67% of infected vs 0% of control rats; p = 0.0013). Infected rats had a higher combined score when determined by the functional observational battery than control rats at all time points (24 h 12.7 ± 4.0 vs 4.0 ± 2.0; 48 h 17.3 ± 7.1 vs 3.4 ± 1.8; 6 days 17.8 ± 7.4 vs 1.7 ± 2.4; p < 0.0001 for all).

CONCLUSIONS

The functional observational battery described here detects clinically relevant neurological sequelae of bacterial meningitis and could be a useful tool when testing new therapeutics in rat models of meningitis.

Segregation within school classes: Detecting social clustering in choice data

We suggest a new method for detecting patterns of social clustering based on choice data. The method compares similar subjects within and between cohorts and thereby allows us to isolate the effect of peer influence from that of exogenous factors. Using this method on Norwegian register data, we address the question of whether students tend to cluster socially based on similar background. We find that common background correlates with making the same choices of curricular tracks, and that both exogenous preferences and peer influence matter. This applies to immigrant students from the same country, and, to some extent, to descendants of immigrants, but not to students from culturally similar countries. There are also small effects related to parents' education and income.

Partial reduction of amyloid β production by β-secretase inhibitors does not decrease synaptic transmission

BACKGROUND

Alzheimer's disease (AD) is the most common form of age-related neurodegenerative diseases. Cerebral deposition of Aβ peptides, especially Aβ42, is considered the major neuropathological hallmark of AD and the putative cause of AD-related neurotoxicity. Aβ peptides are produced by sequential proteolytic processing of APP, with β-secretase (BACE) being the initiating enzyme. Therefore, BACE has been considered an attractive therapeutic target in AD research and several BACE inhibitors have been tested in clinical trials, but so far, all have had negative outcomes or even led to worsening of cognitive function. AD can be triggered by Aβ years before the first symptoms appear and one reason for the failures could be that the clinical trials were initiated too late in the disease process. Another possible explanation could be that BACE inhibition alters physiological APP processing in a manner that impairs synaptic function, causing cognitive deterioration.

METHODS

The aim of this study was to investigate if partial BACE inhibition, mimicking the putative protective effect of the Icelandic mutation in the APP gene, could reduce Aβ generation without affecting synaptic transmission. To investigate this, we used an optical electrophysiology platform, in which effects of compounds on synaptic transmission in cultured neurons can be monitored. We employed this method on primary cortical rat neuronal cultures treated with three different BACE inhibitors (BACE inhibitor IV, LY2886721, and lanabecestat) and monitored Aβ secretion into the cell media.

RESULTS

We found that all three BACE inhibitors tested decreased synaptic transmission at concentrations leading to significantly reduced Aβ secretion. However, low-dose BACE inhibition, resulting in less than a 50% decrease in Aβ secretion, did not affect synaptic transmission for any of the inhibitors tested.

CONCLUSION

Our results indicate that Aβ production can be reduced by up to 50%, a level of reduction of relevance to the protective effect of the Icelandic mutation, without causing synaptic dysfunction. We therefore suggest that future clinical trials aimed at prevention of Aβ build-up in the brain should aim for a moderate CNS exposure of BACE inhibitors to avoid side effects on synaptic function.

Using alcohol consumption diary data from an internet intervention for outcome and predictive modeling: a validation and machine learning study

BACKGROUND

Alcohol use disorder (AUD) is highly prevalent and presents a large treatment gap. Self-help internet interventions are an attractive approach to lowering thresholds for seeking help and disseminating evidence-based programs at scale. Internet interventions for AUD however suffer from high attrition and since continuous outcome measurements are uncommon, little is known about trajectories and processes. The current study investigates whether data from a non-mandatory alcohol consumption diary, common in internet interventions for AUD, approximates drinks reported at follow-up, and whether data from the first half of the intervention predict treatment success.

METHODS

N = 607 participants enrolled in a trial of online self-help for AUD, made an entry in the non-mandatory consumption diary (total of 9117 entries), and completed the follow-up assessment. Using multiple regression and a subset of calendar data overlapping with the follow-up, scaling factors were derived to account for missing entries per participant and week. Generalized estimating equations with an inverse time predictor were then used to calculate point-estimates of drinks per week at follow-up, the confidence intervals of which were compared to that from the measurement at follow-up. Next, calendar data form the first half of the intervention were retained and summary functions used to create 18 predictors for random forest machine learning models, the classification accuracies of which were ultimately estimated using nested cross-validation.

RESULTS

While the raw calendar data substantially underestimated drinks reported at follow-up, the confidence interval of the trajectory-derived point-estimate from the adjusted data overlapped with the confidence interval of drinks reported at follow-up. Machine learning models achieved prediction accuracies of 64% (predicting non-hazardous drinking) and 48% (predicting AUD severity decrease), in both cases with higher sensitivity than specificity.

CONCLUSIONS

Data from a non-mandatory alcohol consumption diary, adjusted for missing entries, approximates follow-up data at a group level, suggesting that such data can be used to reveal trajectories and processes during treatment and possibly be used to impute missing follow-up data. At an individual level, however, calendar data from the first half of the intervention did not have high predictive accuracy, presumable due to a high rate of missing data and unclear missing mechanisms.

Update on the EFFECTS study of fluoxetine for stroke recovery: a randomised controlled trial in Sweden

Studies have suggested that fluoxetine might improve neurological recovery after stroke, but the results remain inconclusive. The EFFECTS (Efficacy oF Fluoxetine - a randomisEd Controlled Trial in Stroke) reached its recruitment target of 1500 patients in June 2019. The purpose of this article is to present all amendments to the protocol and describe how we formed the EFFECTS trial collaboration in Sweden.

METHODS

In this investigator-led, multicentre, parallel-group, randomised, placebo-controlled trial, we enrolled non-depressed stroke patients aged 18 years or older between 2 and 15 days after stroke onset. The patients had a clinical diagnosis of stroke (ischaemic or intracerebral haemorrhage) with persisting focal neurological deficits. Patients were randomised to fluoxetine 20 mg or matching placebo capsules once daily for 6 months.

RESULTS

Seven amendments were made and included clarification of drug interaction between fluoxetine and metoprolol and the use of metoprolol for severe heart failure as an exclusion criterion, inclusion of data from central Swedish registries and the Swedish Stroke Register, changes in informed consent from patients, and clarification of design of some sub-studies. EFFECTS recruited 1500 patients at 35 centres in Sweden between 20 October 2014 and 28 June 2019. We plan to unblind the data in January 2020 and report the primary outcome in May 2020.

CONCLUSION

EFFECTS will provide data on the safety and efficacy of 6 months of treatment with fluoxetine after stroke in a Swedish health system setting. The data from EFFECTS will also contribute to an individual patient data meta-analysis.

TRIAL REGISTRATION

EudraCT 2011-006130-16. Registered on 8 August 2014. ISRCTN, ISRCTN13020412. Registered on 19 December 2014. ClinicalTrials.gov: NCT02683213. Retrospectively registered on 2 February 2016.

Are official confirmed cases and fatalities counts good enough to study the COVID-19 pandemic dynamics? A critical assessment through the case of Italy

As the COVID-19 outbreak is developing the two most frequently reported statistics seem to be the raw confirmed case and case fatalities counts. Focusing on Italy, one of the hardest hit countries, we look at how these two values could be put in perspective to reflect the dynamics of the virus spread. In particular, we find that merely considering the confirmed case counts would be very misleading. The number of daily tests grows, while the daily fraction of confirmed cases to total tests has a change point. It (depending on region) generally increases with strong fluctuations till (around, depending on region) 15-22 March and then decreases linearly after. Combined with the increasing trend of daily performed tests, the raw confirmed case counts are not representative of the situation and are confounded with the sampling effort. This we observe when regressing on time the logged fraction of positive tests and for comparison the logged raw confirmed count. Hence, calibrating model parameters for this virus's dynamics should not be done based only on confirmed case counts (without rescaling by the number of tests), but take also fatalities and hospitalization count under consideration as variables not prone to be distorted by testing efforts. Furthermore, reporting statistics on the national level does not say much about the dynamics of the disease, which are taking place at the regional level. These findings are based on the official data of total death counts up to 15 April 2020 released by ISTAT and up to 10 May 2020 for the number of cases. In this work, we do not fit models but we rather investigate whether this task is possible at all. This work also informs about a new tool to collect and harmonize official statistics coming from different sources in the form of a package for the R statistical environment and presents the "COVID-19 Data Hub."

The relation between local and distal muscle fat infiltration in chronic whiplash using magnetic resonance imaging

The objective of this study was to investigate the relationship between fat infiltration in the cervical multifidi and fat infiltration measured in the lower extremities to move further into understanding the complex signs and symptoms arising from a whiplash trauma. Thirty-one individuals with chronic whiplash associated disorders, stratified into a mild/moderate group and a severe group, together with 31 age- and gender matched controls were enrolled in this study. Magnetic resonance imaging was used to acquire a 3D volume of the neck and of the whole-body. Cervical multifidi was used to represent muscles local to the whiplash trauma and all muscles below the hip joint, the lower extremities, were representing widespread muscles distal to the site of the trauma. The fat infiltration was determined by fat fraction in the segmented images. There was a linear correlation between local and distal muscle fat infiltration (p<0.001, r² = 0.28). The correlation remained significant when adjusting for age and WAD group (p = 0.009) as well as when correcting for age, WAD group and BMI (p = 0.002). There was a correlation between local and distal muscle fat infiltration within the severe WAD group (p = 0.0016, r² = 0.69) and in the healthy group (p = 0.022, r² = 0.17) but not in the mild/moderate group (p = 0.29, r² = 0.06). No significant differences (p = 0.11) in the lower extremities’ MFI between the different groups were found. The absence of differences between the groups in terms of lower extremities’ muscle fat infiltration indicates that, in this particular population, the whiplash trauma has a local effect on muscle fat infiltration rather than a generalized.

Protonated Clusters of Neon and Krypton

We present a study of cationic and protonated clusters of neon and krypton. Recent studies using argon have shown that protonated rare gas clusters can have very different magic sizes than pure, cationic clusters. Here, we find that neon behaves similarly to argon, but that the cationic krypton is more similar to its protonated counterparts than the lighter rare gases are, sharing many of the same magic numbers.

Association of preterm birth with lipid disorders in early adulthood: A Swedish cohort study

BACKGROUND

Preterm birth has previously been linked with cardiovascular disease (CVD) in adulthood. However, associations with lipid disorders (e.g., high cholesterol or triglycerides), which are major risk factors for CVD, have seldom been examined and are conflicting. Clinicians will increasingly encounter adult survivors of preterm birth and will need to understand the long-term health sequelae. We conducted the first large population-based study to determine whether preterm birth is associated with an increased risk of lipid disorders.

METHODS AND FINDINGS

A retrospective national cohort study was conducted of all 2,235,012 persons born as singletons in Sweden during 1973 to 1995 (48.6% women), who were followed up for lipid disorders identified from nationwide inpatient, outpatient, and pharmacy data through 2016 (maximum age 44 years). Cox regression was used to adjust for other perinatal and maternal factors, and co-sibling analyses assessed the potential influence of unmeasured shared familial (genetic and/or environmental) factors. A total of 25,050 (1.1%) persons were identified with lipid disorders in 30.3 million person-years of follow-up. Each additional 5 weeks of gestation were associated with a 14% reduction in risk of lipid disorders (adjusted hazard ratio [HR], 0.86; 95% CI, 0.83-0.89; P < 0.001). Relative to full-term birth (gestational age 39-41 weeks), the adjusted HR associated with preterm birth (<37 weeks) was 1.23 (95% CI, 1.16-1.29; P < 0.001), and further stratified was 2.00 (1.41-2.85; P < 0.001) for extremely preterm (22-27 weeks), 1.33 (1.19-1.49; P < 0.001) for very preterm (28-33 weeks), and 1.19 (1.12-1.26; P < 0.001) for late preterm (34-36 weeks). These findings were similar in men and women (e.g., preterm versus full-term, men: HR, 1.22; 95% CI, 1.14-1.31; P < 0.001; women: HR, 1.23; 1.12-1.32; P < 0.001). Co-sibling analyses suggested that they were substantially though not completely explained by shared genetic or environmental factors in families. The main study limitation was the unavailability of laboratory data to assess specific types or severity of lipid disorders.

CONCLUSIONS

In this large national cohort, preterm birth was associated with an increased risk of lipid disorders in early- to midadulthood. Persons born prematurely may need early preventive evaluation and long-term monitoring for lipid disorders to reduce their future cardiovascular risks.

Decreased physical health-related quality of life-a persisting state for older women with clinical vertebral fracture

In a population-based study of older Swedish women, we investigated if clinical vertebral fracture was associated with lower health-related quality of life (HRQoL) and determined whether the association remained over time. Clinical vertebral fracture was associated with lower HRQoL and the effect persisted for up to 18.9 years.

INTRODUCTION

Vertebral fractures are often associated with back pain and reduced physical function, which might result in isolation and depression. As a result, women with vertebral fractures often have lower health-related quality of life (HRQoL), but during what time frame the decrease lingers is unclear. Therefore, the aim of this study was to investigate if clinical vertebral fracture and hip fracture were associated with lower HRQoL and to determine whether the associations remained over time.

METHODS

Vertebral fracture assessments (VFA) were performed using dual-energy X-ray absorptiometry. Data regarding prior fractures, medications, medical history, and physical activity was collected using a questionnaire. Self-rated physical HRQoL was assessed using the 12-Item Short-Form Health Survey (SF-12). Women with clinical vertebral fractures were divided into tertiles according to time since fracture onset and their HRQoL was compared with non-fractured women.

RESULTS

In a population-based cross-sectional study of 3028 women aged 77.8 ± 1.63 (mean ± SD), a total of 130 (4.3%) women reported at least one clinical vertebral fracture. Women with a clinical vertebral fracture, divided into tertiles (T1-T3) depending on time since the fracture occurred, had lower HRQoL (T1: 36.3 ± 10.8; T2: 41.0 ± 9.94; and T3:41.6 ± 11.4) than women without fracture (46.2 ± 10.6; p < 0.001). Using linear regression analysis, clinical vertebral fracture was associated with reduced physical HRQoL for up to 18.9 years, independently of covariates (age, height, weight, smoking, prior stroke, mental HRQoL, grip strength, and lumbar spine BMD).

CONCLUSIONS

Clinical vertebral fracture was associated with lower self-rated physical HRQoL, for up to 18.9 years after time of fracture.

Why do eukaryotic proteins contain more intrinsically disordered regions?

Intrinsic disorder is more abundant in eukaryotic than prokaryotic proteins. Methods predicting intrinsic disorder are based on the amino acid sequence of a protein. Therefore, there must exist an underlying difference in the sequences between eukaryotic and prokaryotic proteins causing the (predicted) difference in intrinsic disorder. By comparing proteins, from complete eukaryotic and prokaryotic proteomes, we show that the difference in intrinsic disorder emerges from the linker regions connecting Pfam domains. Eukaryotic proteins have more extended linker regions, and in addition, the eukaryotic linkers are significantly more disordered, 38% vs. 12-16% disordered residues. Next, we examined the underlying reason for the increase in disorder in eukaryotic linkers, and we found that the changes in abundance of only three amino acids cause the increase. Eukaryotic proteins contain 8.6% serine; while prokaryotic proteins have 6.5%, eukaryotic proteins also contain 5.4% proline and 5.3% isoleucine compared with 4.0% proline and ≈ 7.5% isoleucine in the prokaryotes. All these three differences contribute to the increased disorder in eukaryotic proteins. It is tempting to speculate that the increase in serine frequencies in eukaryotes is related to regulation by kinases, but direct evidence for this is lacking. The differences are observed in all phyla, protein families, structural regions and type of protein but are most pronounced in disordered and linker regions. The observation that differences in the abundance of three amino acids cause the difference in disorder between eukaryotic and prokaryotic proteins raises the question: Are amino acid frequencies different in eukaryotic linkers because the linkers are more disordered or do the differences cause the increased disorder?

Intrinsic disorder is essential for various functions in eukaryotic cells and is a signature of eukaryotic proteins. Here, we try to understand the origin of the difference in disorder between eukaryotic and prokaryotic proteins. We show that eukaryotic proteins contain more extended linker regions and that these linker regions are significantly more disordered. Further, we show, for the first time, that the difference in disorder originates from a systematic difference in amino acid frequencies between eukaryotic and prokaryotic proteins. Three amino acids contribute to the difference in disorder; serine and proline are more abundant in eukaryotic linkers, while isoleucine is less frequent. These shifts in frequencies are observed in all phyla, protein families, structural regions and type of protein but are most pronounced in disordered and linker regions. It is tempting to speculate that the increase in serine frequencies in eukaryotes is related to regulation by kinases, but direct evidence for this is lacking. Anyhow the widespread of the shifts in abundance indicates that the differences are ancient and caused be some yet not fully understood selective difference acting on eukaryotic and prokaryotic proteins.

Model-inferred mechanisms of liver function from magnetic resonance imaging data: Validation and variation across a clinically relevant cohort

Estimation of liver function is important to monitor progression of chronic liver disease (CLD). A promising method is magnetic resonance imaging (MRI) combined with gadoxetate, a liver-specific contrast agent. For this method, we have previously developed a model for an average healthy human. Herein, we extended this model, by combining it with a patient-specific non-linear mixed-effects modeling framework. We validated the model by recruiting 100 patients with CLD of varying severity and etiologies. The model explained all MRI data and adequately predicted both timepoints saved for validation and gadoxetate concentrations in both plasma and biopsies. The validated model provides a new and deeper look into how the mechanisms of liver function vary across a wide variety of liver diseases. The basic mechanisms remain the same, but increasing fibrosis reduces uptake and increases excretion of gadoxetate. These mechanisms are shared across many liver functions and can now be estimated from standard clinical images.

Being able to accurately and reliably estimate liver function is important when monitoring the progression of patients with liver disease, as well as when identifying drug-induced liver injury during drug development. A promising method for quantifying liver function is to use magnetic resonance imaging combined with gadoxetate. Gadoxetate is a liver-specific contrast agent, which is taken up by the hepatocytes and excreted into the bile. We have previously developed a mechanistic model for gadoxetate dynamics using averaged data from healthy volunteers. In this work, we extended our model with a non-linear mixed-effects modeling framework to give patient-specific estimates of the gadoxetate transport-rates. We validated the model by recruiting 100 patients with liver disease, covering a range of severity and etiologies. All patients underwent an MRI-examination and provided both blood and liver biopsies. Our validated model provides a new and deeper look into how the mechanisms of liver function varies across a wide variety of liver diseases. The basic mechanisms remain the same, but increasing fibrosis reduces uptake and increases excretion of gadoxetate.

Prevalence of intimate partner violence against women in Sweden and Spain: A psychometric study of the 'Nordic paradox'

The high prevalence of intimate partner violence against women (IPVAW) in countries with high levels of gender equality has been defined as the “Nordic paradox”. In this study we compared physical and sexual IPVAW prevalence data in two countries exemplifying the Nordic paradox: Sweden (N = 1483) and Spain (N = 1447). Data was drawn from the European Union Agency for Fundamental Rights Survey on violence against women. To ascertain whether differences between these two countries reflect true differences in IPVAW prevalence, and to rule out the possibility of measurement bias, we conducted a set of analyses to ensure measurement equivalence, a precondition for appropriate and valid cross-cultural comparisons. Results showed that in both countries items were measuring two separate constructs, physical and sexual IPVAW, and that these factors had high internal consistency and adequate validity. Measurement equivalence analyses (i.e., differential item functioning, and multigroup confirmatory factor analysis) supported the comparability of data across countries. Latent means comparisons between the Spanish and the Swedish samples showed that scores on both the physical and sexual IPVAW factors were significantly higher in Sweden than in Spain. The effect sizes of these differences were large: 89.1% of the Swedish sample had higher values in the physical IPVAW factor than the Spanish average, and this percentage was 99.4% for the sexual IPVAW factor as compared to the Spanish average. In terms of probability of superiority, there was an 80.7% and 96.1% probability that a Swedish woman would score higher than a Spanish woman in the physical and the sexual IPVAW factors, respectively. Our results showed that the higher prevalence of physical and sexual IPVAW in Sweden than in Spain reflects actual differences and are not the result of measurement bias, supporting the idea of the Nordic paradox.

A natural history model for planning prostate cancer testing: Calibration and validation using Swedish registry data

Recent prostate cancer screening trials have given conflicting results and it is unclear how to reduce prostate cancer mortality while minimising overdiagnosis and overtreatment. Prostate cancer testing is a partially observable process, and planning for testing requires either extrapolation from randomised controlled trials or, more flexibly, modelling of the cancer natural history. An existing US prostate cancer natural history model (Gulati et al, Biostatistics 2010;11:707-719) did not model for differences in survival between Gleason 6 and 7 cancers and predicted too few Gleason 7 cancers for contemporary Sweden. We re-implemented and re-calibrated the US model to Sweden. We extended the model to more finely describe the disease states, their time to biopsy-detectable cancer and prostate cancer survival. We first calibrated the model to the incidence rate ratio observed in the European Randomised Study of Screening for Prostate Cancer (ERSPC) together with age-specific cancer staging observed in the Stockholm PSA (prostate-specific antigen) and Biopsy Register; we then calibrated age-specific survival by disease states under contemporary testing and treatment using the Swedish National Prostate Cancer Register. After calibration, we were able to closely match observed prostate cancer incidence trends in Sweden. Assuming that patients detected at an earlier stage by screening receive a commensurate survival improvement, we find that the calibrated model replicates the observed mortality reduction in a simulation of ERSPC. Using the resulting model, we predicted incidence and mortality following the introduction of regular testing. Compared with a model of the current testing pattern, organised 8 yearly testing for men aged 55–69 years was predicted to reduce prostate cancer incidence by 14% and increase prostate cancer mortality by 2%. The model is open source and suitable for planning for effective prostate cancer screening into the future.

Activity, social and sexual behaviour in Red Junglefowl selected for divergent levels of fear of humans

The domesticated phenotype is a set of behavioural, morphological and physiological traits that is common for domesticated species. Previous research has found that selection for tameness only can give rise to correlated selection responses that resemble the domesticated phenotype. It has therefore been suggested that tameness may drive the domesticated phenotype as correlated traits. We selected Red Junglefowl for divergent levels of fear of human for eight generations and assessed possible correlated selection responses in other behaviours in semi-natural settings. Behavioural studies were carried out on birds from generations six to eight, and at different ages, in order to study possible effects on general activity, social behaviour and male courtship behaviour. We found that the differences between selection lines changed with age. Adult low fear birds were generally more active and high fear males showed a more intense courtship behaviour. Our study shows that several behaviours can be modified through correlated selection responses by selection on reduced fear of humans only, emphasising the putative role of tameness as a driver of domestication related phenotypes.

Relative survival in patients with dementia with Lewy bodies and Parkinson's disease dementia

INTRODUCTION

The understanding of survival in dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) is limited, as well as the impact of these diagnoses in an ageing co-morbid population.

METHODS

A retrospective study of 177 patients who received a DLB or PDD diagnosis between 1997-2014 at the Memory Clinic in Malmö, Sweden. Relative survival was evaluated by adjusting all-cause survival for expected survival, estimated from population life-tables, matched by sex, age and calendar year. Predictors of relative survival were investigated using multivariate regression modelling.

RESULTS

At follow-up, 143 (81%) patients were deceased with a median survival of 4.1 years (IQR 2.6-6.0). After 10-years follow-up, the standardized mortality ratio was 3.44 (95% CI 2.92-4.04). Relative survival was worse with younger age at diagnosis (excess hazard ratio [eHR] 0.91, 95% CI 0.88-0.94 per year of age), female sex (eHR 1.45, 95% CI 1.01-2.09) and lower mini-mental state examination (eHR 0.93, 95% CI 0.90-0.96). Subgroup analysis (n = 141) showed higher mortality in DLB patients who were positive for APOE ɛ4 (eHR 2.00, 95% CI 1.35-2.97).

CONCLUSION

The mortality is over three-times higher in patients diagnosed with dementia with Lewy bodies and Parkinson's disease dementia during a ten-year follow-up, compared to persons in the general population. Excess mortality is found primarily in younger patients, females and carriers of APOE ε4. Further research is needed regarding survival and possible interventions, including disease-modifying treatments, to improve care for this patient group.

Greater tau load and reduced cortical thickness in APOE ε4-negative Alzheimer's disease: a cohort study

BACKGROUND

Alzheimer's disease is characterized by aggregated β-amyloid and tau proteins, but the clinical presentations and patterns of brain atrophy vary substantially. A part of this heterogeneity may be linked to the risk allele APOE ε4. The spread of tau pathology is related to atrophy and cognitive decline, but little data exist on the effects of APOE ε4 on tau. The objective of this preliminary study was therefore to test if tau load and brain structure differ by APOE ε4 in Alzheimer's disease.

METHODS

Sixty-five β-amyloid-positive patients at the prodromal and dementia stages of Alzheimer's disease were enrolled, including APOE ε4-positive (n = 46) and APOE ε4-negative (n = 19) patients. 18F-AV-1451 positron emission tomography was used to measure tau and brain magnetic resonance imaging (MRI) was used to measure cortical thickness.

RESULTS

Compared with their APOE ε4-positive counterparts, APOE ε4-negative patients had greater tau load and reduced cortical thickness, with the most pronounced effects for both in the parietal cortex. Relative to the overall cortical tau load, APOE ε4-positive patients had greater tau load in the entorhinal cortex. APOE ε4-positive patients also had slightly greater cortical β-amyloid load. There was an interaction between APOE ε4 and 18F-AV-1451 on cortical thickness, with greater effects of 18F-AV-1451 on cortical thickness in APOE ε4-negative patients. APOE ε4 and 18F-AV-1451 were independent predictors of cognition, but showed distinct associations with different cognitive tests.

CONCLUSIONS

APOE genotype may be associated with differences in pathways in Alzheimer's disease, potentially through differential development and spread of tau, as well as through effects on cognitive outcomes involving non-tau-related mechanisms.

Feasibility of sun and magnetic compass mechanisms in avian long-distance migration

Birds use different compass mechanisms based on celestial (stars, sun, skylight polarization pattern) and geomagnetic cues for orientation. Yet, much remains to be understood how birds actually use these compass mechanisms on their long-distance migratory journeys. Here, we assess in more detail the consequences of using different sun and magnetic compass mechanisms for the resulting bird migration routes during both autumn and spring migration. First, we calculated predicted flight routes to determine which of the compasses mechanisms lead to realistic and feasible migration routes starting at different latitudes during autumn and spring migration. We then compared the adaptive values of the different compass mechanisms by calculating distance ratios in relation to the shortest possible trajectory for three populations of nocturnal passerine migrants: northern wheatear Oenanthe oenanthe, pied flycatcher Ficedula hypoleuca, and willow warbler Phylloscopus trochilus. Finally, we compared the predicted trajectories for different compass strategies with observed routes based on recent light-level geolocation tracking results for five individuals of northern wheatears migrating between Alaska and tropical Africa. We conclude that the feasibility of different compass routes varies greatly with latitude, migratory direction, migration season, and geographic location. Routes following a single compass course throughout the migratory journey are feasible for many bird populations, but the underlying compass mechanisms likely differ between populations. In many cases, however, the birds likely have to reorient once to a few times along the migration route and/or use map information to successfully reach their migratory destination.

Dual tracer tau PET imaging reveals different molecular targets for 11C-THK5351 and 11C-PBB3 in the Alzheimer brain

Purpose

Several tau PET tracers have been developed, but it remains unclear whether they bind to the same molecular target on the heterogeneous tau pathology. In this study we evaluated the binding of two chemically different tau-specific PET tracers (¹¹C-THK5351 and ¹¹C-PBB3) in a head-to-head, in vivo, multimodal design.

Methods

Nine patients with a diagnosis of mild cognitive impairment or probable Alzheimer’s disease and cerebrospinal fluid biomarker evidence supportive of the presence of Alzheimer’s disease brain pathology were recruited after thorough clinical assessment. All patients underwent imaging with the tau-specific PET tracers ¹¹C-THK5351 and ¹¹C-PBB3 on the same day, as well as imaging with the amyloid-beta-specific tracer ¹¹C-AZD2184, a T1-MRI sequence, and neuropsychological assessment.

Results

The load and regional distribution of binding differed between ¹¹C-THK5351 and ¹¹C-PBB3 with no statistically significant regional correlations observed between the tracers. The binding pattern of ¹¹C-PBB3, but not that of ¹¹C-THK5351, in the temporal lobe resembled that of ¹¹C-AZD2184, with strong correlations detected between ¹¹C-PBB3 and ¹¹C-AZD2184 in the temporal and occipital lobes. Global cognition correlated more closely with ¹¹C-THK5351 than with ¹¹C-PBB3 binding. Similarly, cerebrospinal fluid tau measures and entorhinal cortex thickness were more closely correlated with ¹¹C-THK5351 than with ¹¹C-PBB3 binding.

Conclusion

This research suggests different molecular targets for these tracers; while ¹¹C-PBB3 appeared to preferentially bind to tau deposits with a close spatial relationship to amyloid-beta, the binding pattern of ¹¹C-THK5351 fitted the expected distribution of tau pathology in Alzheimer’s disease better and was more closely related to downstream disease markers.

Electronic supplementary material

The online version of this article (10.1007/s00259-018-4012-5) contains supplementary material, which is available to authorized users.

Hemodynamic forces in the left and right ventricles of the human heart using 4D flow magnetic resonance imaging: Phantom validation, reproducibility, sensitivity to respiratory gating and free analysis software

Purpose

To investigate the accuracy, reproducibility and sensitivity to respiratory gating, field strength and ventricle segmentation of hemodynamic force quantification in the left and right ventricles of the heart (LV and RV) using 4D-flow magnetic resonance imaging (MRI), and to provide free hemodynamic force analysis software.

Materials and methods

A pulsatile flow phantom was imaged using 4D flow MRI and laser-based particle image velocimetry (PIV). Cardiac 4D flow MRI was performed in healthy volunteers at 1.5T (n = 23). Reproducibility was investigated using MR scanners from two different vendors on the same day (n = 8). Subsets of volunteers were also imaged without respiratory gating (n = 17), at 3T on the same day (n = 6), and 1–12 days later on the same scanner (n = 9, median 6 days). Agreement was measured using the intraclass correlation coefficient (ICC).

Results

Phantom validation showed good accuracy for both scanners (Scanner 1: bias -14±9%, y = 0.82x+0.08, R² = 0.96, Scanner 2: bias -12±8%, y = 0.99x-0.08, R² = 1.00). Force reproducibility was strong in the LV (0.09±0.07 vs 0.09±0.07 N, bias 0.00±0.04 N, ICC = 0.87) and RV (0.09±0.06 vs 0.09±0.05 N, bias 0.00±0.03, ICC = 0.83). Strong to very strong agreement was found for scans with and without respiratory gating (LV/RV: ICC = 0.94/0.95), scans on different days (ICC = 0.92/0.87), and 1.5T and 3T scans (ICC = 0.93/0.94).

Conclusion

Software for quantification of hemodynamic forces in 4D-flow MRI was developed, and results show high accuracy and strong to very strong reproducibility for both the LV and RV, supporting its use for research and clinical investigations. The software including source code is released freely for research.

Maternal suicide - Register based study of all suicides occurring after delivery in Sweden 1974-2009

Background

Recent research suggests that having a newborn child is associated with substantially reduced risk for maternal suicide. We studied postpartum suicides in a national cohort of mothers and the role of mental disorder, self-harm and delivery related factors.

Methods

We used a nested case-control design with data from Swedish registries. The cohort consisted of all women given birth in Sweden 1974–2009. Mothers who died by suicide during follow-up were considered cases (n = 1,786) and risk of suicide was estimated with proximity to delivery as the explanatory variable. In a second step, association between suicide during the first year following delivery (n = 145) and mental disorder, self-harm and delivery related variables risk factors were analyzed.

Results

The first postpartum year was associated with a lower risk of suicide, compared to later (RR 0.80, 95%CI 0.66–0.96), which was unaltered after adjustment for socio-economic status and history of self-harm (aRR 0.82, 95%CI 0.68–0.99). Compared to living mothers, suicide victims of the postpartum year more often had affective disorders (aRR 133.94, 95%CI 45.93–390.61), psychotic disorders (aRR 83.69, 95%CI 36.99–189.31) and history of self-harm (aRR 47.56, 95%CI 18.24–124.02). The aRR of stillbirth was 2.66 (95%CI 0.63–11.30).

Conclusions

We found only a weak negative association between childbirth during the preceding year and suicide, when using mothers as controls. A severe mental disorder after delivery and a history of self-harm was strongly associated with increased risk of suicide in the postpartum year and may inform the clinical assessment postpartum.

Discovery of the fourth mobile sulfonamide resistance gene

BACKGROUND

Over the past 75 years, human pathogens have acquired antibiotic resistance genes (ARGs), often from environmental bacteria. Integrons play a major role in the acquisition of antibiotic resistance genes. We therefore hypothesized that focused exploration of integron gene cassettes from microbial communities could be an efficient way to find novel mobile resistance genes. DNA from polluted Indian river sediments were amplified using three sets of primers targeting class 1 integrons and sequenced by long- and short-read technologies to maintain both accuracy and context.

RESULTS

Up to 89% of identified open reading frames encode known resistance genes, or variations thereof (> 1000). We identified putative novel ARGs to aminoglycosides, beta-lactams, trimethoprim, rifampicin, and chloramphenicol, including several novel OXA variants, providing reduced susceptibility to carbapenems. One dihydropteroate synthase gene, with less than 34% amino acid identity to the three known mobile sulfonamide resistance genes (sul1-3), provided complete resistance when expressed in Escherichia coli. The mobilized gene, here named sul4, is the first mobile sulfonamide resistance gene discovered since 2003. Analyses of adjacent DNA suggest that sul4 has been decontextualized from a set of chromosomal genes involved in folate synthesis in its original host, likely within the phylum Chloroflexi. The presence of an insertion sequence common region element could provide mobility to the entire integron. Screening of 6489 metagenomic datasets revealed that sul4 is already widespread in seven countries across Asia and Europe.

CONCLUSIONS

Our findings show that exploring integrons from environmental communities with a history of antibiotic exposure can provide an efficient way to find novel, mobile resistance genes. The mobilization of a fourth sulfonamide resistance gene is likely to provide expanded opportunities for sulfonamide resistance to spread, with potential impacts on both human and animal health.

Reduced kidney function is associated with BMD, bone loss and markers of mineral homeostasis in older women: a 10-year longitudinal study

Kidney function decreases with age; however, the long-term influence on bone density (BMD) in older women already at risk of osteoporosis is unknown. We followed kidney function and bone loss for 10 years. Declining kidney function was adversely associated with bone loss and mineral homeostasis in old women, though it attenuated with advanced aging.

INTRODUCTION

Existing studies do not fully address the relationship between kidney function and bone metabolism with advanced aging in Caucasian women. This study describes the association between kidney function, BMD, bone loss and bone metabolism in older women and provides a review of the available literature for context.

METHODS

We studied participants from the OPRA cohort with follow-up after 5 and 10 years. Using plasma cystatin C (cysC), estimated glomerular function rate (eGFR) was evaluated at age 75 (n = 981), 80 (n = 685) and 85 (n = 365). Women were stratified into "normal" function (CKD stages 1-2), "intermediate" (stage 3a) and "poor" (stages 3b-5), and outcome measures-BMD, bone loss and markers of mineral homeostasis-were compared.

RESULTS

Femoral neck (FN) BMD positively associated with kidney function at 75 years old ([Formula: see text] = 0.001, p = 0.028) and 80 years old ([Formula: see text] = 0.001, p = 0.001), although with small effect size. Prevalence of osteoporosis (FN T-score ≤ - 2.5) did not differ with kidney function. Measured at age 75, women with poor kidney function had higher annual percentage bone loss over 5 years compared to those with normal function (2.3%, 95% CI 1.8-2.8 versus 1.3%, 95% CI 1.1-1.5, p = 0.007), although not when measured from age 80 or 85. Additionally, markers of mineral homeostasis (PTH, phosphate, vitamin D, calcium), CRP and osteocalcin differed by kidney function.

CONCLUSIONS

In old women, kidney function is associated with BMD, bone loss and altered mineral homeostasis; probably, a relationship attenuated in the very elderly.

"I am Your Mother and Your Father!" In Vitro Derived Gametes and the Ethics of Solo Reproduction

In this paper, we will discuss the prospect of human reproduction achieved with gametes originating from only one person. According to statements by a minority of scientists working on the generation of gametes in vitro, it may become possible to create eggs from men's non-reproductive cells and sperm from women's. This would enable, at least in principle, the creation of an embryo from cells obtained from only one individual: 'solo reproduction'. We will consider what might motivate people to reproduce in this way, and the implications that solo reproduction might have for ethics and policy. We suggest that such an innovation is unlikely to revolutionise reproduction and parenting. Indeed, in some respects it is less revolutionary than in vitro fertilisation as a whole. Furthermore, we show that solo reproduction with in vitro created gametes is not necessarily any more ethically problematic than gamete donation-and probably less so. Where appropriate, we draw parallels with the debate surrounding reproductive cloning. We note that solo reproduction may serve to perpetuate reductive geneticised accounts of reproduction, and that this may indeed be ethically questionable. However, in this it is not unique among other technologies of assisted reproduction, many of which focus on genetic transmission. It is for this reason that a ban on solo reproduction might be inconsistent with continuing to permit other kinds of reproduction that also bear the potential to strengthen attachment to a geneticised account of reproduction. Our claim is that there are at least as good reasons to pursue research towards enabling solo reproduction, and eventually to introduce solo reproduction as an option for fertility treatment, as there are to do so for other infertility related purposes.

PLS3 sequencing in childhood-onset primary osteoporosis identifies two novel disease-causing variants

Altogether 95 children with primary bone fragility were screened for variants in PLS3, the gene underlying X-linked osteoporosis. Two children with multiple peripheral and spinal fractures and low BMD had novel disease-causing PLS3 variants. Children with milder phenotypes had no pathogenic variants. PLS3 screening is indicated in childhood-onset primary osteoporosis.

INTRODUCTION

The study aimed to determine the role of pathogenic PLS3 variants in children's bone fragility and to elucidate the associated phenotypic features.

METHODS

Two cohorts of children with bone fragility were screened for variants in PLS3, the gene underlying X-linked osteoporosis. Cohort I comprised 31 patients with childhood-onset primary osteoporosis of unknown etiology. Cohort II comprised 64 children who had sustained multiple fractures but were otherwise healthy. Clinical and radiological data were reviewed. Peripheral blood DNA was Sanger sequenced for coding exons and flanking intronic regions of PLS3.

RESULTS

In two patients of cohort I, where other common genetic causes had been excluded, we identified two novel disease-causing PLS3 variants. Patient 1 was a male with bilateral femoral fractures at 10 years, low BMD (Z-score -4.1; 18 years), and multiple vertebral compression fractures. He had a novel nonsense variant in PLS3. Patient 2 was a girl with multiple long bone and vertebral fractures and low BMD (Z-score -6.6 at 6 years). She had a de novo missense variant in PLS3; whole exome sequencing and array-CGH identified no other genetic causes. Iliac crest bone biopsies confirmed low-turnover osteoporosis in both patients. In cohort II, no pathogenic PLS3 variants were identified in any of the subjects.

CONCLUSIONS

Two novel disease-causing variants in PLS3 were identified in a boy and a girl with multiple peripheral and spinal fractures and very low BMD while no pathogenic variants were identified in children with less severe skeletal fragility. PLS3 screening is warranted in male and female patients with childhood-onset primary osteoporosis.

Asporin-deficient mice have tougher skin and altered skin glycosaminoglycan content and structure

The main structural component of connective tissues is fibrillar, cross-linked collagen whose fibrillogenesis can be modulated by Small Leucine-Rich Proteins/Proteoglycans (SLRPs). Not all SLRPs’ effects on collagen and extracellular matrix in vivo have been elucidated; one of the less investigated SLRPs is asporin. Here we describe the successful generation of an Aspn^-/- mouse model and the investigation of the Aspn^-/- skin phenotype. Functionally, Aspn^-/- mice had an increased skin mechanical toughness, although there were no structural changes present on histology or immunohistochemistry. Electron microscopy analyses showed 7% thinner collagen fibrils in Aspn^-/- mice (not statistically significant). Several matrix genes were upregulated, including collagens (Col1a1, Col1a2, Col3a1), matrix metalloproteinases (Mmp2, Mmp3) and lysyl oxidases (Lox, Loxl2), while lysyl hydroxylase (Plod2) was downregulated. Intriguingly no differences were observed in collagen protein content or in collagen cross-linking-related lysine oxidation or hydroxylation. The glycosaminoglycan content and structure in Aspn^-/- skin was profoundly altered: chondroitin/dermatan sulfate was more than doubled and had an altered composition, while heparan sulfate was halved and had a decreased sulfation. Also, decorin and biglycan were doubled in Aspn^-/- skin. Overall, asporin deficiency changes skin glycosaminoglycan composition, and decorin and biglycan content, which may explain the changes in skin mechanical properties.

Microwave technology for detecting traumatic intracranial bleedings: tests on phantom of subdural hematoma and numerical simulations

Traumatic brain injury is the leading cause of death and severe disability for young people and a major public health problem for elderly. Many patients with intracranial bleeding are treated too late, because they initially show no symptoms of severe injury and are not transported to a trauma center. There is a need for a method to detect intracranial bleedings in the prehospital setting. In this study, we investigate whether broadband microwave technology (MWT) in conjunction with a diagnostic algorithm can detect subdural hematoma (SDH). A human cranium phantom and numerical simulations of SDH are used. Four phantoms with SDH 0, 40, 70 and 110 mL are measured with a MWT instrument. The simulated dataset consists of 1500 observations. Classification accuracy is assessed using fivefold cross-validation, and a validation dataset never used for training. The total accuracy is 100 and 82-96 % for phantom measurements and simulated data, respectively. Sensitivity and specificity for bleeding detection were 100 and 96 %, respectively, for the simulated data. SDH of different sizes is differentiated. The classifier requires training dataset size in order of 150 observations per class to achieve high accuracy. We conclude that the results indicate that MWT can detect and estimate the size of SDH. This is promising for developing MWT to be used for prehospital diagnosis of intracranial bleedings.

The importance of nonlinear tissue modelling in finite element simulations of infant head impacts

Despite recent efforts on the development of finite element (FE) head models of infants, a model capable of capturing head responses under various impact scenarios has not been reported. This is hypothesized partially attributed to the use of simplified linear elastic models for soft tissues of suture, scalp and dura. Orthotropic elastic constants are yet to be determined to incorporate the direction-specific material properties of infant cranial bone due to grain fibres radiating from the ossification centres. We report here on our efforts in advancing the above-mentioned aspects in material modelling in infant head and further incorporate them into subject-specific FE head models of a newborn, 5- and 9-month-old infant. Each model is subjected to five impact tests (forehead, occiput, vertex, right and left parietal impacts) and two compression tests. The predicted global head impact responses of the acceleration-time impact curves and the force-deflection compression curves for different age groups agree well with the experimental data reported in the literature. In particular, the newly developed Ogden hyperelastic model for suture, together with the nonlinear modelling of scalp and dura mater, enables the models to achieve more realistic impact performance compared with linear elastic models. The proposed approach for obtaining age-dependent skull bone orthotropic material constants counts both an increase in stiffness and decrease in anisotropy in the skull bone-two essential biological growth parameters during early infancy. The profound deformation of infant head causes a large stretch at the interfaces between the skull bones and the suture, suggesting that infant skull fractures are likely to initiate from the interfaces; the impact angle has a profound influence on global head impact responses and the skull injury metrics for certain impact locations, especially true for a parietal impact.

Estimation of Nonlinear Adsorption Isotherms in Gradient Elution RP-LC of Peptides in the Presence of an Adsorbing Additive

ABSTRACT

In electrostatic repulsive interaction chromatography, using a charged surface hybrid sorbent carrying positive charges can improve the peak shape of peptides in reversed-phase liquid chromatography (RP-LC), especially in overloaded conditions, compared with standard C18 sorbents. However, the positive surface charges can interact with anionic additives commonly used in peptide separations, e.g., trifluoroacetic acid (TFA), complicating adsorption isotherm estimation. We investigated how the competition for available adsorption sites between TFA and two peptides influenced the adsorption isotherm in gradient elution. A model accounting for the competition with TFA was compared with a model neglecting TFA adsorption. We found that the two models predicted elution profiles with the same accuracy. We also found that the adsorption isotherms were extremely similar in shape, leading to the conclusion that neglecting the competition with TFA is a valid approximation enabling faster and more robust adsorption isotherm estimation for the studied type of sorbent.

GRAPHICAL ABSTRACT

Potential for hydrogen-oxidizing chemolithoautotrophic and diazotrophic populations to initiate biofilm formation in oligotrophic, deep terrestrial subsurface waters

BACKGROUND

Deep terrestrial biosphere waters are separated from the light-driven surface by the time required to percolate to the subsurface. Despite biofilms being the dominant form of microbial life in many natural environments, they have received little attention in the oligotrophic and anaerobic waters found in deep bedrock fractures. This study is the first to use community DNA sequencing to describe biofilm formation under in situ conditions in the deep terrestrial biosphere.

RESULTS

In this study, flow cells were attached to boreholes containing either "modern marine" or "old saline" waters of different origin and degree of isolation from the light-driven surface of the earth. Using 16S rRNA gene sequencing, we showed that planktonic and attached populations were dissimilar while gene frequencies in the metagenomes suggested that hydrogen-fed, carbon dioxide- and nitrogen-fixing populations were responsible for biofilm formation across the two aquifers. Metagenome analyses further suggested that only a subset of the populations were able to attach and produce an extracellular polysaccharide matrix. Initial biofilm formation is thus likely to be mediated by a few bacterial populations which were similar to Epsilonproteobacteria, Deltaproteobacteria, Betaproteobacteria, Verrucomicrobia, and unclassified bacteria.

CONCLUSIONS

Populations potentially capable of attaching to a surface and to produce extracellular polysaccharide matrix for attachment were identified in the terrestrial deep biosphere. Our results suggest that the biofilm populations were taxonomically distinct from the planktonic community and were enriched in populations with a chemolithoautotrophic and diazotrophic metabolism coupling hydrogen oxidation to energy conservation under oligotrophic conditions.

Human ROBO1 regulates white matter structure in corpus callosum

The axon guidance receptor, Robo1, controls the pathfinding of callosal axons in mice. To determine whether the orthologous ROBO1 gene is involved in callosal development also in humans, we studied polymorphisms in the ROBO1 gene and variation in the white matter structure in the corpus callosum using both structural magnetic resonance imaging and diffusion tensor magnetic resonance imaging. We found that five polymorphisms in the regulatory region of ROBO1 were associated with white matter density in the posterior part of the corpus callosum pathways. One of the polymorphisms, rs7631357, was also significantly associated with the probability of connections to the parietal cortical regions. Our results demonstrate that human ROBO1 may be involved in the regulation of the structure and connectivity of posterior part of corpus callosum.

Asymptotic Robustness Study of the Polychoric Correlation Estimation

Asymptotic robustness against misspecification of the underlying distribution for the polychoric correlation estimation is studied. The asymptotic normality of the pseudo-maximum likelihood estimator is derived using the two-step estimation procedure. The t distribution assumption and the skew-normal distribution assumption are used as alternatives to the normal distribution assumption in a numerical study. The numerical results show that the underlying normal distribution can be substantially biased, even though skewness and kurtosis are not large. The skew-normal assumption generally produces a lower bias than the normal assumption. Thus, it is worth using a non-normal distributional assumption if the normal assumption is dubious.

Setting development goals using stochastic dynamical system models

The Millennium Development Goals (MDG) programme was an ambitious attempt to encourage a globalised solution to important but often-overlooked development problems. The programme led to wide-ranging development but it has also been criticised for unrealistic and arbitrary targets. In this paper, we show how country-specific development targets can be set using stochastic, dynamical system models built from historical data. In particular, we show that the MDG target of two-thirds reduction of child mortality from 1990 levels was infeasible for most countries, especially in sub-Saharan Africa. At the same time, the MDG targets were not ambitious enough for fast-developing countries such as Brazil and China. We suggest that model-based setting of country-specific targets is essential for the success of global development programmes such as the Sustainable Development Goals (SDG). This approach should provide clear, quantifiable targets for policymakers.

Matrix Riemann-Hilbert problems with jumps across Carleson contours

We develop a theory of n × n -matrix Riemann-Hilbert problems for a class of jump contours and jump matrices of low regularity. Our basic assumption is that the contour Γ is a finite union of simple closed Carleson curves in the Riemann sphere. In particular, unbounded contours with cusps, corners, and nontransversal intersections are allowed. We introduce a notion of L p -Riemann-Hilbert problem and establish basic uniqueness results and Fredholm properties. We also investigate the implications of Fredholmness for the unique solvability and prove a theorem on contour deformation.

Prediction of femoral strength using 3D finite element models reconstructed from DXA images: validation against experiments

Computed tomography (CT)-based finite element (FE) models may improve the current osteoporosis diagnostics and prediction of fracture risk by providing an estimate for femoral strength. However, the need for a CT scan, as opposed to the conventional use of dual-energy X-ray absorptiometry (DXA) for osteoporosis diagnostics, is considered a major obstacle. The 3D shape and bone mineral density (BMD) distribution of a femur can be reconstructed using a statistical shape and appearance model (SSAM) and the DXA image of the femur. Then, the reconstructed shape and BMD could be used to build FE models to predict bone strength. Since high accuracy is needed in all steps of the analysis, this study aimed at evaluating the ability of a 3D FE model built from one 2D DXA image to predict the strains and fracture load of human femora. Three cadaver femora were retrieved, for which experimental measurements from ex vivo mechanical tests were available. FE models were built using the SSAM-based reconstructions: using only the SSAM-reconstructed shape, only the SSAM-reconstructed BMD distribution, and the full SSAM-based reconstruction (including both shape and BMD distribution). When compared with experimental data, the SSAM-based models predicted accurately principal strains (coefficient of determination >0.83, normalized root-mean-square error <16%) and femoral strength (standard error of the estimate 1215 N). These results were only slightly inferior to those obtained with CT-based FE models, but with the considerable advantage of the models being built from DXA images. In summary, the results support the feasibility of SSAM-based models as a practical tool to introduce FE-based bone strength estimation in the current fracture risk diagnostics.

Role of DARPP-32 and ARPP-21 in the Emergence of Temporal Constraints on Striatal Calcium and Dopamine Integration

In reward learning, the integration of NMDA-dependent calcium and dopamine by striatal projection neurons leads to potentiation of corticostriatal synapses through CaMKII/PP1 signaling. In order to elicit the CaMKII/PP1-dependent response, the calcium and dopamine inputs should arrive in temporal proximity and must follow a specific (dopamine after calcium) order. However, little is known about the cellular mechanism which enforces these temporal constraints on the signal integration. In this computational study, we propose that these temporal requirements emerge as a result of the coordinated signaling via two striatal phosphoproteins, DARPP-32 and ARPP-21. Specifically, DARPP-32-mediated signaling could implement an input-interval dependent gating function, via transient PP1 inhibition, thus enforcing the requirement for temporal proximity. Furthermore, ARPP-21 signaling could impose the additional input-order requirement of calcium and dopamine, due to its Ca²⁺/calmodulin sequestering property when dopamine arrives first. This highlights the possible role of phosphoproteins in the temporal aspects of striatal signal transduction.

A response towards an environmental stimulus could be reinforced if it elicits a reward. On the subcellular level, the environmental stimulus and the reward signal lead to a transient increase in striatal calcium- and dopamine-signaling, respectively. The integration of calcium and dopamine signals, which is important for reward-learning, could elicit a downstream response only if they are close in time and arrive in correct order (first calcium and then dopamine). This study proposes that the requirement for the input signals to be temporally close and in correct order could emerge due to the coordinated signaling via two striatal phosphoproteins, DARPP-32 and ARPP-21. The DARPP-32 signaling implements an input-interval dependent gating function and ARPP-21 implements an input-order dependent threshold-like function. Thus, a molecular mechanism has been presented here which could explain the emergence of important temporal aspects of subcellular signal integration in reward-learning.