Martin Luther University of Halle-Wittenberg

About: Martin Luther University of Halle-Wittenberg is a education organization based out in Halle, Germany. It is known for research contribution in the topics: Population & Liquid crystal. The organization has 20232 authors who have published 38773 publications receiving 965004 citations. The organization is also known as: MLU & University of Wittenberg.

Biomechanical and histological changes after corneal crosslinking with and without epithelial debridement.

Abstract: Purpose To test the biomechanical efficiency of corneal crosslinking with riboflavin without epithelial debridement (C3-R). Setting Moscow Helmholtz Research Institute of Eye Diseases, Moscow, Russia. Methods The left eyes of rabbits were crosslinked using standard crosslinking including epithelial removal (Group 1), using benzalkonium chloride–containing proxymetacaine eyedrops without epithelial removal (Group 2), or using preservative-free oxybuprocaine eyedrops without epithelial removal (Group 3). All left eyes received riboflavin solution and were irradiated with an ultraviolet-A double diode for 30 minutes (irradiance 3 mW/cm 2 ). The animals were killed 1 day after crosslinking. Biomechanical and histological analyses were performed. Results Fourteen eyes were evaluated. There was a statistically significant increase in Young's modulus in Group 1 (102.45%) and in Group 2 (21.30%). In Group 3, no biomechanical changes were measured. Histology showed complete cell loss of keratocytes and endothelium in Group 1 and inhomogeneous keratocyte loss down to 200.0 μm in Group 2. No changes were observed in Group 3. Conclusions Corneal crosslinking without epithelial debridement reduced the biomechanical effect by approximately one fifth compared with standard crosslinking, probably because of restricted and inhomogeneous stromal distribution of riboflavin. The cytotoxic damage was restricted to 200.0 μm stromal depth, which is an advantage over the standard method. Therefore, C3-R is not recommended for the routine treatment of keratoconus but primarily for cases with a corneal thickness less than 400.0 μm in which standard crosslinking cannot be used without serious risk to the endothelium.

Comb-shaped polymers to enhance hydroxide transport in anion exchange membranes

Abstract: Comb-shaped poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) polymers with quaternary ammonium (QA) groups have been synthesized organizing into well-defined micro-morphology for efficient anion (hydroxide) transport. These molecular comb structures show a dramatic enhancement in conductivity and water resistance compared with non-comb-shaped PPOs.

Endpoints in Adjuvant Treatment Trials: A Systematic Review of the Literature in Colon Cancer and Proposed Definitions for Future Trials

Abstract: Disease-free survival is increasingly being used as the primary endpoint of most trials testing adjuvant treatments in cancer. Other frequently used endpoints include overall survival, recurrence-free survival, and time to recurrence. These endpoints are often defined differently in different trials in the same type of cancer, leading to a lack of comparability among trials. In this Commentary, we used adjuvant studies in colon cancer as a model to address this issue. In a systematic review of the literature, we identified 52 studies of adjuvant treatment in colon cancer published in 1997-2006 that used eight other endpoints in addition to overall survival. Both the definition of these endpoints and the starting point for measuring time to the events that constituted these endpoints varied widely. A panel of experts on clinical research on colorectal cancer then reached consensus on the definition of each endpoint. Disease-free survival--defined as the time from randomization to any event, irrespective of cause--was considered to be the most informative endpoint for assessing the effect of treatment and therefore the most relevant to clinical practice. The proposed guidelines may add to the quality and cross-comparability of future studies of adjuvant treatments for cancer.

Functional integration of hepatocytes derived from human mesenchymal stem cells into mouse livers

Abstract: Aims: At present, clinical success of hepatocyte transplantation as an alternative to whole liver transplantation is hampered by the limited availability of suitable donor organs for the isolation of transplantable hepatocytes. Hence, novel cell sources are required to deliver hepatocytes of adequate quality for clinical use. Mesenchymal stem cells (MSCs) from human bone marrow may have the potential to differentiate into hepatocytes in vitro and in vivo. Methods: Isolated MSCs were selected by density gradient centrifugation and plastic adherence, differentiated in the presence of human hepatocyte growth medium and transplanted in immunodeficient Pfp/Rag2 mice. Results: Here, we demonstrate that human MSCs gain in vitro the characteristic morphology and function of hepatocytes in response to specified growth factors. Specifically, preconditioned MSCs store glycogen, synthesise urea and feature the active hepatocyte-specific gene promoter of phosphoenolpyruvate carboxykinase (PCK1). After transplantation into livers of immunodeficient mice, preconditioned MSCs engraft predominantly in the periportal portion of the liver lobule. In situ, the cells continue to store glycogen and express PCK1, connexin32, albumin and the human hepatocyte-specific antigen HepPar1, indicating that the transplanted cells retain prominent qualities of hepatocytes after their regional integration. Conclusion: MSCs derived from human bone marrow may serve as a novel source for the propagation of hepatocyte-like cells suitable for cell therapy in liver diseases.