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.

Activation, regulation, and inhibition of DYRK1A.

Abstract: Dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) is a protein kinase with diverse functions in neuronal development and adult brain physiology. Higher than normal levels of DYRK1A are associated with the pathology of neurodegenerative diseases and have been implicated in some neurobiological alterations of Down syndrome, such as mental retardation. It is therefore important to understand the molecular mechanisms that control the activity of DYRK1A. Here we review the current knowledge about the initial self-activation of DYRK1A by tyrosine autophosphorylation and propose that this mechanism presents an ancestral feature of the CMGC group of kinases. However, tyrosine phosphorylation does not appear to regulate the enzymatic activity of DYRK1A. Control of DYRK1A may take place on the level of gene expression, interaction with regulatory proteins and regulated nuclear translocation. Finally, we compare the properties of small molecule inhibitors that target DYRK1A and evaluate their potential application and limitations. The β-carboline alkaloid harmine is currently the most selective and potent inhibitor of DYRK1A and has proven very useful in cellular assays.

A guide to the composition and functions of the extracellular matrix.

Abstract: Extracellular matrix (ECM) is a dynamic 3-dimensional network of macromolecules that provides structural support for the cells and tissues. Accumulated knowledge clearly demonstrated over the last decade that ECM plays key regulatory roles since it orchestrates cell signaling, functions, properties and morphology. Extracellularly secreted as well as cell-bound factors are among the major members of the ECM family. Proteins/glycoproteins, such as collagens, elastin, laminins and tenascins, proteoglycans and glycosaminoglycans, hyaluronan, and their cell receptors such as CD44 and integrins, responsible for cell adhesion, comprise a well-organized functional network with significant roles in health and disease. On the other hand, enzymes such as matrix metalloproteinases and specific glycosidases including heparanase and hyaluronidases contribute to matrix remodeling and affect human health. Several cell processes and functions, among them cell proliferation and survival, migration, differentiation, autophagy, angiogenesis, and immunity regulation are affected by certain matrix components. Structural alterations have been also well associated with disease progression. This guide on the composition and functions of the ECM gives a broad overview of the matrisome, the major ECM macromolecules, and their interaction networks within the ECM and with the cell surface, summarizes their main structural features and their roles in tissue organization and cell functions, and emphasizes the importance of specific ECM constituents in disease development and progression as well as the advances in molecular targeting of ECM to design new therapeutic strategies.

Thermodynamic Characterization of Bile Salt Aggregation as a Function of Temperature and Ionic Strength Using Isothermal Titration Calorimetry

Abstract: The critical micellar concentration (cmc) and the demicellization enthalpy ΔHdemic of the primary aggregates of sodium cholate (NaC) and sodium deoxycholate (NaDC) in water and 0.1 M NaCl at pH 7.5 were determined by isothermal titration calorimetry (ITC). The cmc of NaC and NaDC in water and 0.1 M NaCl at pH 7.5 shows a minimum between 295 and 300 K. With increasing ionic strength, the cmc of the bile salts decreases. ΔHdemic is strongly temperature-dependent but shows almost no dependence on the ionic strength. For comparison with other systems, the thermodynamic parameters ΔGdemic and ΔSdemic associated with the demicellization process were calculated using the pseudo-phase-separation model. From the temperature dependence of ΔHdemic, the change in heat capacity ΔCpdemic for the demicellization process was determined. The data obtained for ΔCpdemic are positive and at 298 K have values of 250 J·mol-1·K-1 for NaC and 350 J·mol-1·K-1 for NaDC. These values correspond to changes in the exposed hydrophobic...

Prophylactic thyroidectomy in 75 children and adolescents with hereditary medullary thyroid carcinoma : german and austrian experience

Abstract: RETproto-oncogene were found in 1993 to account for hereditary medullary thyroid carcinoma (MTC), surgeons obtained the opportunity to operate on patients prophylactically (ie, at a clinically asymptomatic stage) Whether this approach is justified, and, if so, when and to which extent surgery should be performed remained to be clarified A questionnaire was sent to all surgical departments in Germany and Austria All of the patients who fulfilled the following criteria were enrolled: (1) preoperatively proved RET mutation; (2) age ≤ 20 years, (3) clinically asymptomatic thyroid C cell disease; and (4) TNM classification pT0–1/pNX/pN0–1/M0 Seventy-five patients were identified, and fifteen mutations were detected in six codons Two adolescents had unilateral pheochromocytomas as part of the multiple endocrine neoplasia II (MEN-II) syndrome No hyperparathyroidism was noted All patients underwent total thyroidectomy, and 57 patients went on to have lymph node dissection Parathyroid glands were removed in 34 patients and autografted in 11 Histopathology revealed MTC in 46 patients (61%, youngest 4 years); C cell hyperplasia (CCH) only was detected in the other 29 patients Three patients had lymph node metastases (LNMs) the youngest being age 14 years Calcitonin levels were not useful for differentiating between CCH and MTC, but in all patients with LNMs at least the stimulated calcitonin levels were assayed After surgery, five patients (67%) sustained permanent hypoparathyroidism, and one patient (13%) had a permanent unilateral recurrent nerve palsy All but three patients (96%) were biochemically cured In conclusion, prophylactic total thyroidectomy can be performed safely in experienced centers We recommend prophylactic total thyroidectomy at age 6 Cervicocentral lymph node dissection should be included when calcitonin levels are elevated or if patients are older than 10 years Bilateral lymph node dissection should be performed if LNMs are suspected or when patients with elevated calcitonin are older than 15 years

Selectivity in analytical chemistry (IUPAC Recommendations 2001)

Abstract: : The correct use of the term “selectivity” and its clear distinction from theterm “specificity” are discussed. A definition of selectivity is given, and it is rec-ommended that the use of this term be promoted and that the use of the term“specificity” be discouraged. 1. INTRODUCTION A very important quality criterion of an analytical method is its capability to deliver signals that are freefrom interferences and give “true results”. The ability to discriminate between the analyte and interfer-ing components has, for many years, been expressed as the “selectivity” of a method and measurementsystem. One clear definition is the following: “ Selectivity of a method refers to the extent to which itcan determine particular analyte(s) in a complex mixture without interference from other componentsin the mixture” [1]. However, the same meaning has often been given to the term “specificity” [2].Following earlier concern about the use of these terms [3] IUPAC clarified this overlap by expressingthe view that “