University of Duisburg-Essen

About: University of Duisburg-Essen is a education organization based out in Essen, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Population & Transplantation. The organization has 16072 authors who have published 39972 publications receiving 1109199 citations.

Mesenchymal stem cell-derived extracellular vesicles ameliorate inflammation-induced preterm brain injury.

Abstract: Objective Preterm brain injury is a major cause of disability in later life, and may result in motor, cognitive and behavioural impairment for which no treatment is currently available. The aetiology is considered as multifactorial, and one underlying key player is inflammation leading to white and grey matter injury. Extracellular vesicles secreted by mesenchymal stem/stromal cells (MSC-EVs) have shown therapeutic potential in regenerative medicine. Here, we investigated the effects of MSC-EV treatment on brain microstructure and maturation, inflammatory processes and long-time outcome in a rodent model of inflammation-induced brain injury. Methods 3-Day-old Wistar rats (P3) were intraperitoneally injected with 0.25 mg/kg lipopolysaccharide or saline and treated with two repetitive doses of 1 × 10 8 cell equivalents of MSC-EVs per kg bodyweight. Cellular degeneration and reactive gliosis at P5 and myelination at P11 were evaluated by immunohistochemistry and western blot. Long-term cognitive and motor function was assessed by behavioural testing. Diffusion tensor imaging at P125 evaluated long-term microstructural white matter alterations. Results MSC-EV treatment significantly ameliorated inflammation-induced neuronal cellular degeneration reduced microgliosis and prevented reactive astrogliosis. Short-term myelination deficits and long-term microstructural abnormalities of the white matter were restored by MSC-EV administration. Morphological effects of MSC-EV treatment resulted in improved long-lasting cognitive functions Interpretation MSC-EVs ameliorate inflammation-induced cellular damage in a rat model of preterm brain injury. MSC-EVs may serve as a novel therapeutic option by prevention of neuronal cell death, restoration of white matter microstructure, reduction of gliosis and long-term functional improvement.

A generalized ESPRIT approach to direction-of-arrival estimation

Abstract: A new spectral search-based direction-of-arrival (DOA) estimation method is proposed that extends the idea of the conventional ESPRIT DOA estimator to a much more general class of array geometries than assumed by the conventional ESPRIT technique. A computationally efficient polynomial rooting-based search-free implementation of the proposed algorithm is also developed.

The biomechanics of restricted movement in adult obesity

Abstract: In spite of significant advances in the knowledge and understanding of the multi-factorial nature of obesity, many questions regarding the specific consequences of the disease remain unanswered. In particular, there is a relative dearth of information pertaining to the functional limitations imposed by overweight and obesity. The limited number of studies to date have mainly focused on the effect of obesity on the temporospatial characteristics of walking, plantar foot pressures, muscular strength and, to a lesser extent, postural balance. Collectively, these studies have implied that the functional limitations imposed by the additional loading of the locomotor system in obesity result in aberrant mechanics and the potential for musculoskeletal injury. Despite the greater prevalence of musculoskeletal disorders in the obese, there has been surprisingly little empirical investigation pertaining to the biomechanics of activities of daily living or into the mechanical and neuromuscular factors that may predispose the obese to injury. A better appreciation of the implications of increased levels of body adiposity on the movement capabilities of the obese would afford a greater opportunity to provide meaningful support in preventing, treating and managing the condition and its sequelae. Moreover, there is an urgent need to establish the physical consequences of continued repetitive loading of major structures of the body, particularly of the lower limbs in the obese, during the diverse range of activities of daily living.

Modeling laser-induced incandescence of soot: a summary and comparison of LII models

Abstract: We have performed a comparison of ten models that predict the temporal behavior of laser-induced incandescence (LII) of soot. In this paper we present a summary of the models and comparisons of calculated temperatures, diameters, signals, and energy-balance terms. The models were run assuming laser heating at 532 nm at fluences of 0.05 and 0.70 J/cm(2) with a laser temporal profile provided. Calculations were performed for a single primary particle with a diameter of 30 nm at an ambient temperature of 1800 K and a pressure of 1 bar. Preliminary calculations were performed with a fully constrained model. The comparison of unconstrained models demonstrates a wide spread in calculated LII signals. Many of the differences can be attributed to the values of a few important parameters, such as the refractive-index function E(m) and thermal and mass accommodation coefficients. Constraining these parameters brings most of the models into much better agreement with each other, particularly for the low-fluence case. Agreement among models is not as good for the high-fluence case, even when selected parameters are constrained. The reason for greater variability in model results at high fluence appears to be related to solution approaches to mass and heat loss by sublimation.

TERT Promoter Mutation Status as an Independent Prognostic Factor in Cutaneous Melanoma

Abstract: Melanomas are characterized by recurrent mutations of oncogenes such as BRAF (v-Raf murine sarcoma viral oncogene homolog) (1), NRAS (neuroblastoma RAS viral oncogene homolog) (2), and KIT (v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog) (3), and tumor suppressor genes including CDKN2A and PTEN (4,5). Recent whole-exome sequencing studies have identified a host of additional genetic events (6,7), many of which occur only in a small proportion of tumors, or in combination with other genetic events. The clinical relevance of these recently identified genetic events, such as putative activating mutations in PPP6C, STK19, RAC1 (6,7), and TRRAP (8), remains to be seen. Whole-exome sequencing approaches focus on enriching and sequencing protein-coding regions of DNA, neglecting most noncoding DNA sequences. This could be the reason why only a few mutations in regulatory DNA domains have been described to date. Recently, two independent studies identified frequent mutations in the promoter region of the TERT (telomerase reverse transcriptase) gene, encoding the catalytic subunit of the telomerase holoenzyme (9,10). Horn et al. identified TERT promoter mutations in a melanoma-prone family, in which affected members developed melanomas at a very young age with near 100% penetrance (10). Subsequently, recurrent mutations at other locations in the TERT promoter were identified in 33% of sporadic primary melanomas and 74% of melanoma cell lines. Huang et al. screened whole-genome sequencing data of melanomas and found that, apart from mutations in BRAF and NRAS, recurrent TERT promoter mutations were the most frequent genomic alterations (9). They validated their findings in a cohort of 70 melanoma samples and short-term cultures, of which 50 (71%) harbored recurrent TERT promoter mutations (9). Functional studies by both groups showed that the promoter mutations led to a 2–4–fold increase in gene expression, most likely a result of the mutations creating ETS transcription factor binding sites (9,10). Subsequent studies have identified TERT promoter mutations in a wide array of human cancers, including bladder cancer, hepatocellular carcinoma, thyroid cancer, and different types of gliomas (11–14). Killela et al. suggested that high frequencies of TERT promoter mutations occurred in tumors arising in tissues with low rates of self-renewal (11). The goals of our study were to analyze the frequency of TERT promoter mutations in a large cohort of melanomas: a) to determine if the types and frequency of mutations varied between melanoma subtypes, b) to establish whether TERT promoter mutations were associated with prognosis, and c) to ascertain their prevalence in the germ line of patients with sporadic cutaneous melanoma.