Increased total tau (t-tau) in cerebrospinal fluid (CSF) is a key characteristic of Alzheimer's disease (AD) and is considered to result from neurodegeneration. T-tau levels, however, can be ...increased in very early disease stages, when neurodegeneration is limited, and can be normal in advanced disease stages. This suggests that t-tau levels may be driven by other mechanisms as well. Because tau pathophysiology is emerging as treatment target for AD, we aimed to clarify molecular processes associated with CSF t-tau levels.
We performed a proteomic, genomic, and imaging study in 1380 individuals with AD, in the preclinical, prodromal, and mild dementia stage, and 380 controls from the Alzheimer's Disease Neuroimaging Initiative and EMIF-AD Multimodality Biomarker Discovery study.
We found that, relative to controls, AD individuals with increased t-tau had increased CSF concentrations of over 400 proteins enriched for neuronal plasticity processes. In contrast, AD individuals with normal t-tau had decreased levels of these plasticity proteins and showed increased concentrations of proteins indicative of blood-brain barrier and blood-CSF barrier dysfunction, relative to controls. The distinct proteomic profiles were already present in the preclinical AD stage and persisted in prodromal and dementia stages implying that they reflect disease traits rather than disease states. Dysregulated plasticity proteins were associated with SUZ12 and REST signaling, suggesting aberrant gene repression. GWAS analyses contrasting AD individuals with and without increased t-tau highlighted several genes involved in the regulation of gene expression. Targeted analyses of SNP rs9877502 in GMNC, associated with t-tau levels previously, correlated in individuals with AD with CSF concentrations of 591 plasticity associated proteins. The number of APOE-e4 alleles, however, was not associated with the concentration of plasticity related proteins.
CSF t-tau levels in AD are associated with altered levels of proteins involved in neuronal plasticity and blood-brain and blood-CSF barrier dysfunction. Future trials may need to stratify on CSF t-tau status, as AD individuals with increased t-tau and normal t-tau are likely to respond differently to treatment, given their opposite CSF proteomic profiles.
This article examines to what extent and how the presence of gazelles, young high-impact firms, is related to the growth of industries over time. For this purpose, we analyze gazelles in The ...Netherlands over a 12-year period, annually from 1997 until 2008, and relate them to the dynamics of industry employment. We use a panel vector autoregressive model to explore the relationship between the prevalence of gazelles in an industry and industry employment growth, in an economy-wide dataset including 43 two-digit industries. An increase in the prevalence of gazelles in an industry appears to have a positive effect on subsequent industry growth. We do not find evidence of an inverse causal relationship: there are no long-run positive effects of increases in industry growth on the prevalence of gazelles. There is also no relationship between overrepresentation of gazelles and subsequent industry growth. PUBLICATION ABSTRACT
Large individual differences exist in the ability to delay gratification for the sake of satisfying longer-term goals. These individual differences are commonly assayed by studying intertemporal ...preferences, as revealed by choices between immediate and delayed rewards. In the brain, reward-based and goal-oriented decisions are believed to rely on the striatum and its interactions with other cortical and subcortical networks. However, it remains unknown which specific cortical-striatal tracts are involved in intertemporal decision making. We use connectivity analyses in both structural and functional MRI to further our understanding of the relationship between distinct corticostriatal networks and intertemporal preferences in humans. Our results revealed distinct striatal pathways that are differentially related to delay discounting. Structural and functional connectivity between striatum and lateral prefrontal cortex was associated with increased patience, whereas connectivity between subcortical areas and striatum was associated with increased impulsivity. These findings provide novel insights into how the anatomy and functioning of striatal circuits mediate individual differences in intertemporal choice.
Objectives
To determine whether there is a difference in frequency and clinical relevance of incidental findings detected by total-body computed tomography scanning (TBCT) compared to those by the ...standard work-up (STWU) with selective computed tomography (CT) scanning.
Methods
Trauma patients from five trauma centres were randomized between April 2011 and January 2014 to TBCT imaging or STWU consisting of conventional imaging with selective CT scanning. Incidental findings were divided into three categories: 1) major finding, may cause mortality; 2) moderate finding, may cause morbidity; and 3) minor finding, hardly relevant. Generalized estimating equations were applied to assess differences in incidental findings.
Results
In total, 1083 patients were enrolled, of which 541 patients (49.9 %) were randomized for TBCT and 542 patients (50.1 %) for STWU. Major findings were detected in 23 patients (4.3 %) in the TBCT group compared to 9 patients (1.7 %) in the STWU group (adjusted rate ratio 2.851; 95%CI 1.337–6.077;
p
< 0.007). Findings of moderate relevance were detected in 120 patients (22.2 %) in the TBCT group compared to 86 patients (15.9 %) in the STWU group (adjusted rate ratio 1.421; 95%CI 1.088–1.854;
p
< 0.010).
Conclusions
Compared to selective CT scanning, more patients with clinically relevant incidental findings can be expected by TBCT scanning.
Key points
•
Total
-
body CT scanning in trauma results in 1.5 times more incidental findings
.
•
Evaluation by TBCT in trauma results in more patients with incidental findings
.
•
In every category of clinical relevance
,
TBCT detects more incidental findings
.
In this article, we compare standard approaches used to handle losses in logarithmic profit models with a simple novel approach. We estimate translog stochastic profit frontiers, and discuss ...discriminatory power, rank stability and the precision of Profit Efficiency (PE) scores. Contrary to existing methods, our approach does not result in a loss of observations. Our new method enhances rank stability and discriminatory power, and improves the precision of PE scores.
Abstract
This manuscript describes the follow-up study of our previous publication on the presence and risks of nanosilica in food. New information on the presence of nanosilica in the ...gastrointestinal tract is evaluated and information on nanosilica and synthetic amorphous silica (SAS) is compared to assess its relevance for risk assessment of nanosilica in food. Irrespective of whether SAS should be regarded as a nanomaterial or a non-nanoform of silica, a comparison to nanosilica is relevant to determine whether there are differences in physicochemical properties, which may lead to differences in toxicity. Based on this comparison, knowledge gaps are identified and recommendations for a targeted approach to facilitate risk assessment of nanosilica in food are given. Considering the discussion to which extent nanomaterials with (slightly) different physicochemical characteristics can be grouped for risk assessment - the sameness issue - actual exercises as presented in this manuscript are highly relevant for bringing this discussion forward.
Abstract
Background
Adequate MRI-based staging of early rectal cancers is essential for decision-making in an era of organ-conserving treatment approaches. The aim of this population-based study was ...to determine the accuracy of routine daily MRI staging of early rectal cancer, whether or not combined with endorectal ultrasonography (ERUS).
Methods
Patients with cT1–2 rectal cancer who underwent local excision or total mesorectal excision (TME) without downsizing (chemo)radiotherapy between 1 January 2011 and 31 December 2018 were selected from the Dutch ColoRectal Audit. The accuracy of imaging was expressed as sensitivity, specificity, and positive predictive value (PPV) and negative predictive value.
Results
Of 7382 registered patients with cT1–2 rectal cancer, 5539 were included (5288 MRI alone, 251 MRI and ERUS; 1059 cT1 and 4480 cT2). Among patients with pT1 tumours, 54·7 per cent (792 of 1448) were overstaged by MRI alone, and 31·0 per cent (36 of 116) by MRI and ERUS. Understaging of pT2 disease occurred in 8·2 per cent (197 of 2388) and 27·9 per cent (31 of 111) respectively. MRI alone overstaged pN0 in 17·3 per cent (570 of 3303) and the PPV for assignment of cN0 category was 76·3 per cent (2733 of 3583). Of 834 patients with pT1 N0 disease, potentially suitable for local excision, tumours in 253 patients (30·3 per cent) were staged correctly as cT1 N0, whereas 484 (58·0 per cent) and 97 (11·6 per cent) were overstaged as cT2 N0 and cT1–2 N1 respectively.
Conclusion
This Dutch population-based analysis of patients who underwent local excision or TME surgery for cT1–2 rectal cancer based on preoperative MRI staging revealed substantial overstaging, indicating the weaknesses of MRI and missed opportunities for organ preservation strategies.
Graphical Abstract
This population-based study determined the accuracy of routine daily MRI staging of early rectal cancer, whether or not combined with endorectal ultrasonography. The results showed that preoperative MRI led to substantial overstaging in patients who underwent local excision or total mesorectal incision surgery for cT1–2 rectal cancer, indicating the weaknesses of MRI and missed opportunities for organ preservation strategies.
Graphical Abstract
Imaging weakness
Necrotizing enterocolitis (NEC) predominantly occurs in preterm infants (PT-NEC). In term neonates, NEC occurs more frequently when a congenital heart disease is present (CHDNEC). Our aim was to ...evaluate differences and similarities in disease characteristics of PT-NEC versus CHD-NEC.
In this retrospective case–control study we identified all CHD infants who developed NEC Bell's stage ≥2 in our center from 2004 to 2014. We randomly selected (1:2 ratio) PT-NEC infants from the same period. Biochemical and clinical variables were retrieved from patient files.
We found 18 CHD-NEC infants and selected 36 PT-NEC infants (gestational age 28.3 25–35.6 weeks vs. 38.6 31.7–40.7 weeks). Postnatal age at onset was significantly lower in CHD-NEC patients (4 2–24 vs. 11 4–41 days, p < 0.001). Lowest pH levels were lower (7.21 7.01–7.47 vs. 7.27 6.68–7.39, p = 0.02), and highest CRP levels were higher (112.5 mg/L 5.0–425.0 vs. 66.0 5.2–189.0, p = 0.05) in PT-NEC vs. CHD-NEC. Anatomic localisation of the disease differed: the colon was significantly more often involved in CHD-NEC versus PT-NEC (86% vs. 33%, p = 0.03). Mortality caused by NEC was not different (22% vs. 11%, p = 0.47).
While outcome of NEC in both groups is similar, the predominant NEC localisation differed between CHD-NEC and PT-NEC patients. This suggests that both variants of the disease have a different underlying pathophysiological mechanism that predisposes different intestinal regions to develop NEC.
Retrospective Case–Control Study.
Level III.
The neuro-anatomical substrates of major depressive disorder (MDD) are still not well understood, despite many neuroimaging studies over the past few decades. Here we present the largest ever ...worldwide study by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Major Depressive Disorder Working Group on cortical structural alterations in MDD. Structural T1-weighted brain magnetic resonance imaging (MRI) scans from 2148 MDD patients and 7957 healthy controls were analysed with harmonized protocols at 20 sites around the world. To detect consistent effects of MDD and its modulators on cortical thickness and surface area estimates derived from MRI, statistical effects from sites were meta-analysed separately for adults and adolescents. Adults with MDD had thinner cortical gray matter than controls in the orbitofrontal cortex (OFC), anterior and posterior cingulate, insula and temporal lobes (Cohen's d effect sizes: -0.10 to -0.14). These effects were most pronounced in first episode and adult-onset patients (>21 years). Compared to matched controls, adolescents with MDD had lower total surface area (but no differences in cortical thickness) and regional reductions in frontal regions (medial OFC and superior frontal gyrus) and primary and higher-order visual, somatosensory and motor areas (d: -0.26 to -0.57). The strongest effects were found in recurrent adolescent patients. This highly powered global effort to identify consistent brain abnormalities showed widespread cortical alterations in MDD patients as compared to controls and suggests that MDD may impact brain structure in a highly dynamic way, with different patterns of alterations at different stages of life.
Introduction
Neurofilament light (NfL), chitinase‐3‐like protein 1 (YKL‐40), and neurogranin (Ng) are biomarkers for Alzheimer's disease (AD) to monitor axonal damage, astroglial activation, and ...synaptic degeneration, respectively.
Methods
We performed genome‐wide association studies (GWAS) using DNA and cerebrospinal fluid (CSF) samples from the EMIF‐AD Multimodal Biomarker Discovery study for discovery, and the Alzheimer's Disease Neuroimaging Initiative study for validation analyses. GWAS were performed for all three CSF biomarkers using linear regression models adjusting for relevant covariates.
Results
We identify novel genome‐wide significant associations between DNA variants in TMEM106B and CSF levels of NfL, and between CPOX and YKL‐40. We confirm previous work suggesting that YKL‐40 levels are associated with DNA variants in CHI3L1.
Discussion
Our study provides important new insights into the genetic architecture underlying interindividual variation in three AD‐related CSF biomarkers. In particular, our data shed light on the sequence of events regarding the initiation and progression of neuropathological processes relevant in AD.
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