Goethe University Frankfurt

About: Goethe University Frankfurt is a education organization based out in Frankfurt am Main, Hessen, Germany. It is known for research contribution in the topics: Population & Transplantation. The organization has 33342 authors who have published 69743 publications receiving 2409538 citations. The organization is also known as: Johann Wolfgang Goethe-Universität Frankfurt am Main & University of Frankfurt am Main.

Bone Tissue Engineering using human mesenchymal stem cells: effects of scaffold material and medium flow

Abstract: We report studies of bone tissue engineering using human mesenchymal stem cells (MSCs), a protein substrate (film or scaffold; fast degrading unmodified collagen, or slowly degrading cross-linked collagen and silk), and a bioreactor (static culture, spinner flask, or perfused cartridge). MSCs were isolated from human bone marrow, characterized for the expression of cell surface markers and the ability to undergo chondrogenesis and osteogenesis in vitro, and cultured for 5 weeks. MSCs were positive for CD105/endoglin, and had a potential for chondrogenic and osteogenic differentiation. In static culture, calcium deposition was similar for MSC grown on collagen scaffolds and films. Under medium flow, MSC on collagen scaffolds deposited more calcium and had a higher alcaline phosphatase (AP) activity than MSC on collagen films. The amounts of DNA were markedly higher in constructs based on slowly degrading (modified collagen and silk) scaffolds than on fast degrading (unmodified collagen) scaffolds. In spinner flasks, medium flow around constructs resulted in the formation of bone rods within the peripheral region, that were interconnected and perpendicular to the construct surface, whereas in perfused constructs, individual bone rods oriented in the direction of fluid flow formed throughout the construct volume. These results suggest that osteogenesis in cultured MSC can be modulated by scaffold properties and flow environment.

Correlation and process in species distribution models: bridging a dichotomy

Abstract: Within the field of species distribution modelling an apparent dichotomy exists between process-based and correlative approaches, where the processes are explicit in the former and implicit in the latter. However, these intuitive distinctions can become blurred when comparing species distribution modelling approaches in more detail. In this review article, we contrast the extremes of the correlative–process spectrum of species distribution models with respect to core assumptions, model building and selection strategies, validation, uncertainties, common errors and the questions they are most suited to answer. The extremes of such approaches differ clearly in many aspects, such as model building approaches, parameter estimation strategies and transferability. However, they also share strengths and weaknesses. We show that claims of one approach being intrinsically superior to the other are misguided and that they ignore the process–correlation continuum as well as the domains of questions that each approach is addressing. Nonetheless, the application of process-based approaches to species distribution modelling lags far behind more correlative (process-implicit) methods and more research is required to explore their potential benefits. Critical issues for the employment of species distribution modelling approaches are given, together with a guideline for appropriate usage. We close with challenges for future development of process-explicit species distribution models and how they may complement current approaches to study species distributions.

Preoperative chemoradiotherapy and postoperative chemotherapy with fluorouracil and oxaliplatin versus fluorouracil alone in locally advanced rectal cancer: initial results of the German CAO/ARO/AIO-04 randomised phase 3 trial

Abstract: Summary Background Preoperative chemoradiotherapy, total mesorectal excision surgery, and adjuvant chemotherapy with fluorouracil is the standard combined modality treatment for rectal cancer. With the aim of improving disease-free survival (DFS), this phase 3 study (CAO/ARO/AIO-04) integrated oxaliplatin into standard treatment. Methods This was a multicentre, open-label, randomised, phase 3 study in patients with histologically proven carcinoma of the rectum with clinically staged T3–4 or any node-positive disease. Between July 25, 2006, and Feb 26, 2010, patients were randomly assigned to two groups: a control group receiving standard fluorouracil-based combined modality treatment, consisting of preoperative radiotherapy of 50·4 Gy plus infusional fluorouracil (1000 mg/m 2 days 1–5 and 29–33), followed by surgery and four cycles of bolus fluorouracil (500 mg/m 2 days 1–5 and 29; fluorouracil group); and an experimental group receiving preoperative radiotherapy of 50·4 Gy plus infusional fluorouracil (250 mg/m 2 days 1–14 and 22–35) and oxaliplatin (50 mg/m 2 days 1, 8, 22, and 29), followed by surgery and eight cycles of adjuvant chemotherapy with oxaliplatin (100 mg/m 2 days 1 and 15), leucovorin (400 mg/m 2 days 1 and 15), and infusional fluorouracil (2400 mg/m 2 days 1–2 and 15–16; fluorouracil plus oxaliplatin group). Randomisation was done with computer-generated block-randomisation codes stratified by centre, clinical T category (cT1–4 vs cT4), and clinical N category (cN0 vs cN1–2) without masking. DFS is the primary endpoint. Secondary endpoints, including toxicity, compliance, and histopathological response are reported here. Safety and compliance analyses included patients as treated, efficacy endpoints were analysed according to the intention-to-treat principle. This study is registered with ClinicalTrials.gov, number NCT00349076. Findings Of the 1265 patients initially enrolled, 1236 were evaluable (613 in the fluorouracil plus oxaliplatin group and 623 in the fluorouracil group). Preoperative grade 3–4 toxic effects occurred in 140 (23%) of 606 patients who actually received fluorouracil and oxaliplatin during chemoradiotherapy and in 127 (20%) of 624 patients who actually received fluorouracil chemoradiotherapy. Grade 3–4 diarrhoea was more common in those who received fluorouracil and oxaliplatin during chemoradiotherapy than in those who received fluorouracil during chemoradiotherapy (73 patients [12%] vs 52 patients [8%]), as was grade 3–4 nausea or vomiting (23 [4%] vs nine [1%]). 516 (85%) of the 606 patients who received fluorouracil and oxaliplatin-based chemoradiotherapy had the full dose of chemotherapy, and 571 (94%) had the full dose of radiotherapy; as did 495 (79%) and 601 (96%) of 624 patients who received fluorouracil-based chemoradiotherapy, respectively. A pathological complete response was achieved in 103 (17%) of 591 patients who underwent surgery in the fluorouracil and oxaliplatin group and in 81 (13%) of 606 patients who underwent surgery in the fluorouracil group (odds ratio 1·40, 95% CI 1·02–1·92; p=0·038). In the fluorouracil and oxaliplatin group, 352 (81%) of 435 patients who began adjuvant chemotherapy completed all cycles (with or without dose reduction), as did 386 (83%) of 463 patients in the fluorouracil group. Interpretation Inclusion of oxaliplatin into modified fluorouracil-based combined modality treatment was feasible and led to more patients achieving a pathological complete response than did standard treatment. Longer follow-up is needed to assess DFS. Funding German Cancer Aid (Deutsche Krebshilfe).

Development and validation of the global map of irrigation areas

Abstract: . A new version of a digital global map of irrigation areas was developed by combining irrigation statistics for 10 825 sub-national statistical units and geo-spatial information on the location and extent of irrigation schemes. The map shows the percentage of each 5 arc minute by 5 arc minute cell that was equipped for irrigation around the year 2000. It is thus an important data set for global studies related to water and land use. This paper describes the data set and the mapping methodology and gives, for the first time, an estimate of the map quality at the scale of countries, world regions and the globe. Two indicators of map quality were developed for this purpose, and the map was compared to irrigated areas as derived from two remote sensing based global land cover inventories.