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Background
Eye movement abnormalities are commonplace in neurological disorders. However, unaided eye movement assessments lack granularity. Although videooculography (VOG) improves diagnostic accuracy, resource intensiveness precludes its broad use. To bridge this care gap, we here validate a framework for smartphone video-based nystagmography capitalizing on recent computer vision advances.
Methods
A convolutional neural network was fine-tuned for pupil tracking using > 550 annotated frames: ConVNG. In a cross-sectional approach, slow-phase velocity of optokinetic nystagmus was calculated in 10 subjects using ConVNG and VOG. Equivalence of accuracy and precision was assessed using the “two one-sample t-test” (TOST) and Bayesian interval-null approaches. ConVNG was systematically compared to OpenFace and MediaPipe as computer vision (CV) benchmarks for gaze estimation.
Results
ConVNG tracking accuracy reached 9–15% of an average pupil diameter. In a fully independent clinical video dataset, ConVNG robustly detected pupil keypoints (median prediction confidence 0.85). SPV measurement accuracy was equivalent to VOG (TOST p < 0.017; Bayes factors (BF) > 24). ConVNG, but not MediaPipe, achieved equivalence to VOG in all SPV calculations. Median precision was 0.30°/s for ConVNG, 0.7°/s for MediaPipe and 0.12°/s for VOG. ConVNG precision was significantly higher than MediaPipe in vertical planes, but both algorithms’ precision was inferior to VOG.
Conclusions
ConVNG enables offline smartphone video nystagmography with an accuracy comparable to VOG and significantly higher precision than MediaPipe, a benchmark computer vision application for gaze estimation. This serves as a blueprint for highly accessible tools with potential to accelerate progress toward precise and personalized Medicine.
Introduction
The term primary progressive aphasia (PPA) sums up the non‐fluent (nfv), the semantic (sv), and the logopenic (lv) variant. Up to now, there is only limited data available concerning magnetic resonance imaging volumetry to monitor disease progression.
Methods
Structural brain imaging and an extensive assessment were applied at baseline and up to 4‐year(s) follow‐up in 269 participants. With automated atlas‐based volumetry 56 brain regions were assessed. Atrophy progression served to calculate sample sizes for therapeutic trials.
Results
At baseline highest atrophy appeared in parts of the left frontal lobe for nfvPPA (–17%) and of the left temporal lobe for svPPA (–34%) and lvPPA (–24%). Severest progression within 1‐year follow‐up occurred in the basal ganglia in nfvPPA (–7%), in the hippocampus/amygdala in svPPA (–9%), and in (medial) temporal regions in lvPPA (–6%).
Conclusion
PPA presents as a left‐dominant, mostly gray matter sensitive disease with considerable atrophy at baseline that proceeds variant‐specific.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that causes progressive autonomy loss and need for care. This does not only affect patients themselves, but also the patients’ informal caregivers (CGs) in their health, personal and professional lives. The big efforts of this multi-center study were not only to evaluate the caregivers' burden and to identify its predictors, but it also should provide a specific understanding of the needs of ALS patients' CGs and fill the gap of knowledge on their personal and work lives. Using standardized questionnaires, primary data from patients and their main informal CGs (n = 249) were collected. Patients' functional status and disease severity were evaluated using the Barthel Index, the revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) and the King’s Stages for ALS. The caregivers' burden was recorded by the Zarit Burden Interview (ZBI). Comorbid anxiety and depression of caregivers were assessed by the Hospital Anxiety and Depression Scale. Additionally, the EuroQol Five Dimension Five Level Scale evaluated their health-related quality of life. The caregivers' burden was high (mean ZBI = 26/88, 0 = no burden, ≥24 = highly burdened) and correlated with patients' functional status (r\(_p\) = −0.555, p < 0.001, n = 242). It was influenced by the CGs' own mental health issues due to caregiving (+11.36, 95% CI [6.84; 15.87], p < 0.001), patients' wheelchair dependency (+9.30, 95% CI [5.94; 12.66], p < 0.001) and was interrelated with the CGs' depression (r\(_p\) = 0.627, p < 0.001, n = 234), anxiety (r\(_p\) = 0.550, p < 0.001, n = 234), and poorer physical condition (r\(_p\) = −0.362, p < 0.001, n = 237). Moreover, female CGs showed symptoms of anxiety more often, which also correlated with the patients' impairment in daily routine (r\(_s\) = −0.280, p < 0.001, n = 169). As increasing disease severity, along with decreasing autonomy, was the main predictor of caregiver burden and showed to create relevant (negative) implications on CGs' lives, patient care and supportive therapies should address this issue. Moreover, in order to preserve the mental and physical health of the CGs, new concepts of care have to focus on both, on not only patients but also their CGs and gender-associated specific issues. As caregiving in ALS also significantly influences the socioeconomic status by restrictions in CGs' work lives and income, and the main reported needs being lack of psychological support and a high bureaucracy, the situation of CGs needs more attention. Apart from their own multi-disciplinary medical and psychological care, more support in care and patient management issues is required.
Fluorinated groups are essential for drug design, agrochemicals, and materials science. The bis(trifluoromethyl)amino group is an example of a stable group that has a high potential. While the number of molecules containing perfluoroalkyl, perfluoroalkoxy, and other fluorinated groups is steadily increasing, examples with the N(CF\(_{3}\))\(_{2}\) group are rare. One reason is that transfer reagents are scarce and metal-based storable reagents are unknown. Herein, a set of Cu\(^{I}\) and Ag\(^{I}\) bis(trifluoromethyl)amido complexes stabilized by N- and P-donor ligands with unprecedented stability are presented. The complexes are stable solids that can even be manipulated in air for a short time. They are bis(trifluoromethyl)amination reagents as shown by nucleophilic substitution and Sandmeyer reactions. In addition to a series of benzylbis(trifluoromethyl)amines, 2-bis(trifluoromethyl)amino acetate was obtained, which, upon hydrolysis, gives the fluorinated amino acid N,N-bis(trifluoromethyl)glycine.
Improving quality of life (QoL) is central to amyotrophic lateral sclerosis (ALS) treatment. This Germany-wide, multicenter cross-sectional study analyses the impact of different symptom-specific treatments and ALS variants on QoL. Health-related QoL (HRQoL) in 325 ALS patients was assessed using the Amyotrophic Lateral Sclerosis Assessment Questionnaire 5 (ALSAQ-5) and EuroQol Five Dimension Five Level Scale (EQ-5D-5L), together with disease severity (captured by the revised ALS Functional Rating Scale (ALSFRS-R)) and the current care and therapies used by our cohort. At inclusion, the mean ALSAQ-5 total score was 56.93 (max. 100, best = 0) with a better QoL associated with a less severe disease status (β = −1.96 per increase of one point in the ALSFRS-R score, p < 0.001). “Limb-onset” ALS (lALS) was associated with a better QoL than “bulbar-onset” ALS (bALS) (mean ALSAQ-5 total score 55.46 versus 60.99, p = 0.040). Moreover, with the ALSFRS-R as a covariate, using a mobility aid (β = −7.60, p = 0.001), being tracheostomized (β = −14.80, p = 0.004) and using non-invasive ventilation (β = −5.71, p = 0.030) were associated with an improved QoL, compared to those at the same disease stage who did not use these aids. In contrast, antidepressant intake (β = 5.95, p = 0.007), and increasing age (β = 0.18, p = 0.023) were predictors of worse QoL. Our results showed that the ALSAQ-5 was better-suited for ALS patients than the EQ-5D-5L. Further, the early and symptom-specific clinical management and supply of assistive devices can significantly improve the individual HRQoL of ALS patients. Appropriate QoL questionnaires are needed to monitor the impact of treatment to provide the best possible and individualized care.
Background
Telemedicine improves the quality of acute stroke care in rural regions with limited access to specialized stroke care. We report the first 2 years' experience of implementing a comprehensive telemedical stroke network comprising all levels of stroke care in a defined region.
Methods
The TRANSIT-Stroke network covers a mainly rural region in north-western Bavaria (Germany). All hospitals providing acute stroke care in this region participate in TRANSIT-Stroke, including four hospitals with a supra-regional certified stroke unit (SU) care (level III), three of those providing teleconsultation to two hospitals with a regional certified SU (level II) and five hospitals without specialized SU care (level I). For a two-year-period (01/2015 to 12/2016), data of eight of these hospitals were available; 13 evidence-based quality indicators (QIs) related to processes during hospitalisation were evaluated quarterly and compared according to predefined target values between level-I- and level-II/III-hospitals.
Results
Overall, 7881 patients were included (mean age 74.6 years +/- 12.8; 48.4% female). In level-II/III-hospitals adherence of all QIs to predefined targets was high ab initio. In level-I-hospitals, three patterns of QI-development were observed: a) high adherence ab initio (31%), mainly in secondary stroke prevention; b) improvement over time (44%), predominantly related to stroke specific diagnosis and in-hospital organization; c) no clear time trends (25%). Overall, 10 out of 13 QIs reached predefined target values of quality of care at the end of the observation period.
Conclusion
The implementation of the comprehensive TRANSIT-Stroke network resulted in an improvement of quality of care in level-I-hospitals.
Background
With upcoming therapeutic interventions for patients with primary progressive aphasia (PPA), instruments for the follow-up of patients are needed to describe disease progression and to evaluate potential therapeutic effects. So far, volumetric brain changes have been proposed as clinical endpoints in the literature, but cognitive scores are still lacking. This study followed disease progression predominantly in language-based performance within 1 year and defined a PPA sum score which can be used in therapeutic interventions.
Methods
We assessed 28 patients with nonfluent variant PPA, 17 with semantic variant PPA, 13 with logopenic variant PPA, and 28 healthy controls in detail for 1 year. The most informative neuropsychological assessments were combined to a sum score, and associations between brain atrophy were investigated followed by a sample size calculation for clinical trials.
Results
Significant absolute changes up to 20% in cognitive tests were found after 1 year. Semantic and phonemic word fluency, Boston Naming Test, Digit Span, Token Test, AAT Written language, and Cookie Test were identified as the best markers for disease progression. These tasks provide the basis of a new PPA sum score. Assuming a therapeutic effect of 50% reduction in cognitive decline for sample size calculations, a number of 56 cases is needed to find a significant treatment effect. Correlations between cognitive decline and atrophy showed a correlation up to r = 0.7 between the sum score and frontal structures, namely the superior and inferior frontal gyrus, as well as with left-sided subcortical structures.
Conclusion
Our findings support the high performance of the proposed sum score in the follow-up of PPA and recommend it as an outcome measure in intervention studies.
High-Sensitivity Troponin: A Clinical Blood Biomarker for Staging Cardiomyopathy in Fabry Disease
(2016)
Background
High‐sensitivity troponin (hs‐TNT), a biomarker of myocardial damage, might be useful for assessing fibrosis in Fabry cardiomyopathy. We performed a prospective analysis of hs‐TNT as a biomarker for myocardial changes in Fabry patients and a retrospective longitudinal follow‐up study to assess longitudinal hs‐TNT changes relative to fibrosis and cardiomyopathy progression.
Methods and Results
For the prospective analysis, hs‐TNT from 75 consecutive patients with genetically confirmed Fabry disease was analyzed relative to typical Fabry‐associated echocardiographic findings and total myocardial fibrosis as measured by late gadolinium enhancement (LE) on magnetic resonance imaging. Longitudinal data (3.9±2.0 years), including hs‐TNT, LE, and echocardiographic findings from 58 Fabry patients, were retrospectively collected. Hs‐TNT level positively correlated with LE (linear correlation coefficient, 0.72; odds ratio, 32.81 [95% CI, 3.56–302.59]; P=0.002); patients with elevated baseline hs‐TNT (>14 ng/L) showed significantly increased LE (median: baseline, 1.9 [1.1–3.3] %; follow‐up, 3.2 [2.3–4.9] %; P<0.001) and slightly elevated hs‐TNT (baseline, 44.7 [30.1–65.3] ng/L; follow‐up, 49.1 [27.6–69.5] ng/L; P=0.116) during follow‐up. Left ventricular wall thickness and EF of patients with elevated hs‐TNT were decreased during follow‐up, indicating potential cardiomyopathy progression.
Conclusions
hs‐TNT is an accurate, easily accessible clinical blood biomarker for detecting replacement fibrosis in patients with Fabry disease and a qualified predictor of cardiomyopathy progression. Thus, hs‐TNT could be helpful for staging and follow‐up of Fabry patients.
Here, we report a continuous flow synthesis of nano LDH, comprising a continuous precipitation process using static mixers and followed by an immediate cleaning process via a semi-continuous centrifuge to obtain the final product in one-go. Via this synthesis setup, it is possible to independently vary the concentrations of the reactants during precipitation and at the same time ensure constant reaction conditions and an immediate "quenching" of the precipitate due to "on the flow"-washing. We found that this paves the way to adjust the synthesis parameters in a way that the final morphology of the nano-LDH particles can be controlled to be either round or platelet-like.
Eukaryotic cells are considered as evolutionary complex organisms because they possess organelles that enable them to regulate the spatio-temporal organization of cellular processes. Spatio-temporal organization of signal transduction cascades occurs in eukaryotic cells via organization of membrane-associated microdomains or lipid rafts. Lipid rafts are nanoscale-sized domains in the plasma membrane that are constituted by a specific set of lipids and proteins and harbor a number of proteins related to signal transduction and trafficking. The integrity of lipid rafts is important for the assembly and functional coordination of a plethora of signaling networks and associated processes. This integrity is partially mediated by a chaperone protein called flotillin. Disruption of lipid raft integrity, for example via depletion or overproduction of flotillin, alters raft-associated signal transduction cascades and causes severe diseases like Alzheimer’s, Parkinson’s disease or cardiovascular disease.
It was traditionally assumed that a sophisticated compartmentalization of cellular processes like the one exhibited in lipid rafts was exclusive to eukaryotic cells and therefore, lipid rafts have been considered as a hallmark in the evolution of cellular complexity, suggesting that prokaryotic cells were too simple organisms to organize such sophisticated membrane platforms. However, it was recently discovered that bacteria are also able to organize Functional Membrane Microdomains (FMMs) in their cellular membrane that are able to organize and catalyze the functionality of many diverse cellular processes. These FMMs of bacterial membranes contain flotillin-like proteins which play important roles in the organization of FMM-associated cellular processes.
In this dissertation I describe the structural and biological significance of the existence of two distinct flotillin proteins, FloA and FloT, in the FMMs of the bacterial model Bacillus subtilis. Localization studies, proteomic data and transcriptomic analyses show that FloA and FloT are individual scaffold proteins that activate different regulatory programs during bacterial growth. Using the tractable bacterial model system, I show that the functionality of important regulatory proteins, like the protease FtsH or the signaling kinases KinC, PhoR and ResE, is linked to the activity of FMMs and that this is a direct consequence of the scaffold activity of the bacterial flotillins. FloA and FloT distribute heterogeneously along the FMMs of B. subtilis thereby generating a heterogeneous population of FMMs that compartmentalize different signal transduction cascades. Interestingly, diversification of FMMs does not occur randomly, but rather in a controlled spatio-temporal program to ensure the activation of given signaling networks at the right place and time during cell growth.