Entwicklung Konformations-spezifischer Amyloid-beta Antikörper

Alzheimer's Disease (AD) is the major cause of dementia in the elderly with over 35 million people suffering as of 2012. The total annual costs generated by dementia are expected to rise to more than 1,100 billion $within the next 15 years. The main cause of the neurodegeneration in AD is believed to be due to a shift in the equilibrium between production and clearance of Amyloid-beta (AB). When produced in excess, AB aggregates to amyloid plaques and causes neuronal dysfunction. The current diagnosis of AD is performed by cognitive function tests and imaging methods that can only detect advanced neuronal degradation. For an accurate identification of the disease at an early stage it is essential to get insight on the biological processes in the brain of AD patients and monitor the aggregation of AB under physiological conditions. Highly selective antibodies that can distinguish between the different forms of AB monomers, oligomers and mature fibrils can fill the gap that still exists in the current understanding of AD. The objective of this work was to generate conformational specific antibodies that fulfill these goals and characterize their biochemical and biophysical properties. For this, two AB42 specific phage display libraries were constructed and screened together with two established naive human libraries for selective binders. Eight individual scFvs were obtained, transferred into the scFv-Fc format and produced in both formats in mammalian cells. Five antibodies were produced in sufficient amounts for additional assays. These scFvs detected different epitopes in AB42 and exhibited affinities to various aggregates in the micromolar to nanomolar range. While three of the five scFvs investigated demonstrated a general specificity towards AB, PaD213-A5 and PaD233-E5 presented a tendency to certain forms of AB42. PaD213-A5 is highly specific for mature AB42 fibrils and was able to distinguish between various fibrillar structures depending on the acidity of the surrounding milieu during fibrillogenesis while PaD233-E5, albeit binding also oligomers and fibrils, showed a 100fold increased affinity towards monomers. Further assessment of the impact on aggregation and toxicity in vitro determined that PaD97-D6, PaD233-E5 and PaD236-H2 are able to inhibit the formation of AB42 fibrils from monomers in a concentration dependent manner and all antibodies were able to rescue the negative effect of AB42 on the metabolism of SH-SY5Y cells.Die Alzheimer Erkrankung (AD) ist die Hauptursache für Demenzerkrankungen in der älteren Bevölkerungsschicht und betrifft weltweit 35 Millionen Menschen. Durch Demenzerkrankungen entstehende Kosten werden in den nächsten 15 Jahren voraussichtlich auf über 1,1 Billionen US$ steigen. Die Neurodegeneration, die der AD zugrunde liegt, wird wahrscheinlich ausgelöst durch die Verschiebung des Gleichgewichts zwischen der Produktion und Beseitigung von Amyloid-beta (AB). Bei erhöhten Konzentrationen aggregiert AB zu Plaques und löst neuronale Fehlfunktionen aus. Die derzeitige Diagnose der AD beruht vor allem auf kognitiven Tests und verschiedenen bildgebenden Verfahren, wodurch allerdings nur eine weit vorangeschrittene Erkrankung identifizierbar ist. Um AD in einem frühen Stadium zu erkennen ist es unerlässlich, einen Einblick in die der Krankheit zugrunde liegenden Prozesse im Gehirn zu erlangen, und das Aggregationsverhalten von AB zu erforschen. Antikörper (AK), die zwischen Aggregaten von AB wie Monomeren, Oligomeren oder Fibrillen differenzieren, können in Zukunft helfen Lücken im derzeitigen Verständnis der AD zu schließen. Das Ziel dieser Arbeit war es, konfirmationsspezifische AK zu generieren, die eben diese Aufgabe erfüllen, und sie mit Hilfe von biochemischen und biophysikalischen Methoden zu charakterisieren. Hierfür wurden zwei AB42 spezifische Phagen-Display-AK-Bibliotheken generiert und zusammen mit zwei naiven Bibliotheken auf Binder untersucht. Es wurden acht scFvs gewonnen, ins scFv-Fc Format überführt und anschließend in beiden Formaten in Mammalia-Zellen produziert. Fünf dieser AK wurden in ausreichenden Konzentrationen für weitere Experimente produziert. Die AK banden an unterschiedliche Epitope von AB42 und wiesen Affinitäten zu mehreren Aggregaten im mikromolarem bis nanomolarem Bereich auf. Drei der untersuchten AK zeigten eine generelle Spezifität zu AB, während zwei AK bestimmte Formen bevorzugten. PaD213-A5 ist hochspezifisch für AB42 Fibrillen und kann zwischen unterschiedlichen fibrillären Strukturen unterscheiden, wohingegen PaD233-E5, obwohl dieser AK alle AB Aggregate detektierte, eine 100fach erhöhte Affinität zu AB42 Monomeren aufwies. Außerdem wurde der AK-Einfluss auf die Aggregation und Toxizität von AB42 in vitro untersucht, wobei PaD97-D6, PaD233-E5 und PaD236-H2 eine Inhibierung der Fibrillogenese herbeiführten und alle scFvs den hemmenden Einfluss von AB42 auf den Zellmetabolismus von SH-SY5Y Zellen verringerten

Deep-Learning based segmentation and quantification in experimental kidney histopathology

BACKGROUND: Nephropathologic analyses provide important outcomes-related data in experiments with the animal models that are essential for understanding kidney disease pathophysiology. Precision medicine increases the demand for quantitative, unbiased, reproducible, and efficient histopathologic analyses, which will require novel high-throughput tools. A deep learning technique, the convolutional neural network, is increasingly applied in pathology because of its high performance in tasks like histology segmentation. METHODS: We investigated use of a convolutional neural network architecture for accurate segmentation of periodic acid-Schiff-stained kidney tissue from healthy mice and five murine disease models and from other species used in preclinical research. We trained the convolutional neural network to segment six major renal structures: glomerular tuft, glomerulus including Bowman\u27s capsule, tubules, arteries, arterial lumina, and veins. To achieve high accuracy, we performed a large number of expert-based annotations, 72,722 in total. RESULTS: Multiclass segmentation performance was very high in all disease models. The convolutional neural network allowed high-throughput and large-scale, quantitative and comparative analyses of various models. In disease models, computational feature extraction revealed interstitial expansion, tubular dilation and atrophy, and glomerular size variability. Validation showed a high correlation of findings with current standard morphometric analysis. The convolutional neural network also showed high performance in other species used in research-including rats, pigs, bears, and marmosets-as well as in humans, providing a translational bridge between preclinical and clinical studies. CONCLUSIONS: We developed a deep learning algorithm for accurate multiclass segmentation of digital whole-slide images of periodic acid-Schiff-stained kidneys from various species and renal disease models. This enables reproducible quantitative histopathologic analyses in preclinical models that also might be applicable to clinical studies

Alcohol mixed with energy drink (AMED): A critical review and meta-analysis

© 2018 The Authors Human Psychopharmacology: Clinical and Experimental Published by John Wiley & Sons Ltd. The purpose of this systematic review and meta-analysis was to critically review the (1) prevalence of alcohol mixed with energy drink (AMED) consumption, (2) motives for AMED consumption, (3) correlates of AMED consumption, and (4) whether AMED consumption has an impact on (a) alcohol consumption, (b) subjective intoxication, and (c) risk-taking behavior. Overall a minority of the population consumes AMED, typically infrequently. Motives for AMED consumption are predominantly hedonistic and social. Meta-analyses revealed that AMED consumers drink significantly more alcohol than alcohol-only (AO) consumers. Within-subject comparisons restricted to AMED consumers revealed that alcohol consumption does not significantly differ between typical AMED and AO occasions. On past month heaviest drinking occasions, AMED users consume significantly less alcohol on AMED occasions when compared to AO occasions. AMED consumers experience significantly fewer negative consequences and risk-taking behavior on AMED occasions compared with AO occasions. Meta-analyses of subjective intoxication studies suggest that AMED consumption does not differentially affect subjective intoxication when compared to AO consumption. In conclusion, when compared to AO consumption, mixing alcohol with energy drink does not affect subjective intoxication and seems unlikely to increase total alcohol consumption, associated risk-taking behavior, nor other negative alcohol-related consequences. Further research may be necessary to fully reveal the effects of AMED

Mapping cardiac remodeling in chronic kidney disease

Patients with advanced chronic kidney disease (CKD) mostly die from sudden cardiac death and recurrent heart failure. The mechanisms of cardiac remodeling are largely unclear. To dissect molecular and cellular mechanisms of cardiac remodeling in CKD in an unbiased fashion, we performed left ventricular single-nuclear RNA sequencing in two mouse models of CKD. Our data showed a hypertrophic response trajectory of cardiomyocytes with stress signaling and metabolic changes driven by soluble uremia-related factors. We mapped fibroblast to myofibroblast differentiation in this process and identified notable changes in the cardiac vasculature, suggesting inflammation and dysfunction. An integrated analysis of cardiac cellular responses to uremic toxins pointed toward endothelin-1 and methylglyoxal being involved in capillary dysfunction and TNFα driving cardiomyocyte hypertrophy in CKD, which was validated in vitro and in vivo. TNFα inhibition in vivo ameliorated the cardiac phenotype in CKD. Thus, interventional approaches directed against uremic toxins, such as TNFα, hold promise to ameliorate cardiac remodeling in CKD.</p

Automated telephone communication systems for preventive healthcare and management of long-term conditions

Background Automated telephone communication systems (ATCS) can deliver voice messages and collect health-related information from patients using either their telephone’s touch-tone keypad or voice recognition software. ATCS can supplement or replace telephone contact between health professionals and patients. There are four different types of ATCS: unidirectional (one-way, non-interactive voice communication), interactive voice response (IVR) systems, ATCS with additional functions such as access to an expert to request advice (ATCS Plus) and multimodal ATCS, where the calls are delivered as part of a multicomponent intervention. Objectives To assess the effects of ATCS for preventing disease and managing long-term conditions on behavioural change, clinical, process, cognitive, patient-centred and adverse outcomes. Search methods We searched 10 electronic databases (the Cochrane Central Register of Controlled Trials; MEDLINE; Embase; PsycINFO; CINAHL; Global Health; WHOLIS; LILACS; Web of Science; and ASSIA); three grey literature sources (Dissertation Abstracts, Index to Theses, Australasian Digital Theses); and two trial registries (www.controlled-trials.com; www.clinicaltrials.gov) for papers published between 1980 and June 2015. Selection criteria Randomised, cluster- and quasi-randomised trials, interrupted time series and controlled before-and-after studies comparing ATCS interventions, with any control or another ATCS type were eligible for inclusion. Studies in all settings, for all consumers/carers, in any preventive healthcare or long term condition management role were eligible. Data collection and analysis We used standard Cochrane methods to select and extract data and to appraise eligible studies. Main results We included 132 trials (N = 4,669,689). Studies spanned across several clinical areas, assessing many comparisons based on evaluation of different ATCS types and variable comparison groups. Forty-one studies evaluated ATCS for delivering preventive healthcare, 84 for managing long-term conditions, and seven studies for appointment reminders. We downgraded our certainty in the evidence primarily because of the risk of bias for many outcomes. We judged the risk of bias arising from allocation processes to be low for just over half the studies and unclear for the remainder. We considered most studies to be at unclear risk of performance or detection bias due to blinding, while only 16% of studies were at low risk. We generally judged the risk of bias due to missing data and selective outcome reporting to be unclear. For preventive healthcare, ATCS (ATCS Plus, IVR, unidirectional) probably increase immunisation uptake in children (risk ratio (RR) 1.25, 95% confidence interval (CI) 1.18 to 1.32; 5 studies, N = 10,454; moderate certainty) and to a lesser extent in adolescents (RR 1.06, 95% CI 1.02 to 1.11; 2 studies, N = 5725; moderate certainty). The effects of ATCS in adults are unclear (RR 2.18, 95% CI 0.53 to 9.02; 2 studies, N = 1743; very low certainty). For screening, multimodal ATCS increase uptake of screening for breast cancer (RR 2.17, 95% CI 1.55 to 3.04; 2 studies, N = 462; high certainty) and colorectal cancer (CRC) (RR 2.19, 95% CI 1.88 to 2.55; 3 studies, N = 1013; high certainty) versus usual care. It may also increase osteoporosis screening. ATCS Plus interventions probably slightly increase cervical cancer screening (moderate certainty), but effects on osteoporosis screening are uncertain. IVR systems probably increase CRC screening at 6 months (RR 1.36, 95% CI 1.25 to 1.48; 2 studies, N = 16,915; moderate certainty) but not at 9 to 12 months, with probably little or no effect of IVR (RR 1.05, 95% CI 0.99, 1.11; 2 studies, 2599 participants; moderate certainty) or unidirectional ATCS on breast cancer screening. Appointment reminders delivered through IVR or unidirectional ATCS may improve attendance rates compared with no calls (low certainty). For long-term management, medication or laboratory test adherence provided the most general evidence across conditions (25 studies, data not combined). Multimodal ATCS versus usual care showed conflicting effects (positive and uncertain) on medication adherence. ATCS Plus probably slightly (versus control; moderate certainty) or probably (versus usual care; moderate certainty) improves medication adherence but may have little effect on adherence to tests (versus control). IVR probably slightly improves medication adherence versus control (moderate certainty). Compared with usual care, IVR probably improves test adherence and slightly increases medication adherence up to six months but has little or no effect at longer time points (moderate certainty). Unidirectional ATCS, compared with control, may have little effect or slightly improve medication adherence (low certainty). The evidence suggested little or no consistent effect of any ATCS type on clinical outcomes (blood pressure control, blood lipids, asthma control, therapeutic coverage) related to adherence, but only a small number of studies contributed clinical outcome data. The above results focus on areas with the most general findings across conditions. In condition-specific areas, the effects of ATCS varied, including by the type of ATCS intervention in use. Multimodal ATCS probably decrease both cancer pain and chronic pain as well as depression (moderate certainty), but other ATCS types were less effective. Depending on the type of intervention, ATCS may have small effects on outcomes for physical activity, weight management, alcohol consumption, and diabetes mellitus. ATCS have little or no effect on outcomes related to heart failure, hypertension, mental health or smoking cessation, and there is insufficient evidence to determine their effects for preventing alcohol/ substance misuse or managing illicit drug addiction, asthma, chronic obstructive pulmonary disease, HIV/AIDS, hypercholesterolaemia, obstructive sleep apnoea, spinal cord dysfunction or psychological stress in carers. Only four trials (3%) reported adverse events, and it was unclear whether these were related to the intervention

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to &lt;90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], &gt;300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of &lt;15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P&lt;0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P&lt;0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Assessment of physiological state of microorganisms in activated sludge with flow cytometry: Application for monitoring sludge production minimization

International audienceMany sludge reduction processes have been studied for the minimization of sludge production in biological wastewater treatment. The investigations on most of these processes have monitored the increase of the soluble chemical oxygen demand, the sludge mass reduction, or the decrease of the floc size, but little information has been obtained on cell lysis and the change of the biological cell activity. However, employing any strategy for reducing sludge production may have an impact of microbial community in biological wastewater treatment process. This impact may influence the sludge characteristics and the quality of effluent. The objective of this study concerns the determination of the physiological state of activated sludge microorganisms during a sludge minimization process. A thermal treatment at 80 °C for 5, 20, 40 and 60 min was chosen in this study. Staining bacteria with CTC and SYTOX green was used to evaluate biological cell activity and viability of cell types contained in activated sludge, respectively. The monitoring of cell activity and viability was performed using flow cytometry (FCM) analysis before and after thermal treatment of activated sludge. Results indicated an increase in the number of permeabilized cells and a decrease in the number of active cells, subsequent to the thermal treatment. The study also confirms the potential of FCM to successfully evaluate the physiological heterogeneity of an activated sludge bacterial population. Moreover, the experimentally observed correlations between the FCM results and the organic matter solubilization in activated sludge samples during thermal treatment revealed that the increase in the soluble organic matter concentration was predominantly due to an intracellular material release. Identifying the increase in activated sludge hydrolysis requires a precise knowledge of the involved mechanisms, and this study indicated that the FCM, used in conjunction with specific probes, could be a useful tool