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.

The genetics of position-effect variegation modifying loci in Drosophila melanogaster

Abstract: The dose dependent effects of position-effect variegation (PEV) modifying genes were studied in chromosome arms2L, 2R and3R. Four groups of PEV modifying genes can be distinguished: haplo-abnormal suppressor and enhancer loci with or without a triplo-effect. using duplications four triplo-abnormal suppressor and four triplo-abnormal enhancer functions were localized. In two cases we proved that these functions correspond to a converse haplo-abnormal one. Altogether 43 modifier loci were identified. Most of these loci proved not to display significant triplo-effects (35). The group of haplo-abnormal loci with a triplo-effect may represent genes which play an important role in heterochromatin packaging.

Pyroglutamate formation influences solubility and amyloidogenicity of amyloid peptides.

Abstract: N-Terminally truncated and pyroglutamate (pGlu) modified amyloid beta (Abeta) peptides are major constituents of amyloid deposits in sporadic and inherited Alzheimer's disease (AD). Formation of pGlu at the N-terminus confers resistance against cleavage by most aminopeptidases, increases toxicity of the peptides, and may seed Abeta aggregate formation. Similarly, the deposited amyloid peptides ABri and ADan, which cause a very similar histopathology in familial British dementia (FBD) and familial Danish dementia (FDD), are N-terminally blocked by pGlu. Triggered by the coincidence of pGlu-modified amyloid peptides and similar pathology in AD, FBD, and FDD, we investigated the impact of N-terminal pGlu on biochemical and biophysical properties of Abeta, ABri, and ADan. N-Terminal pGlu increases the hydrophobicity and changes the pH-dependent solubility profile, rendering the pGlu-modified peptides less soluble in the basic pH range. The pGlu residue increases the aggregation propensity of all amyloid peptides as evidenced by ThT fluorescence assays and dynamic light scattering. The far-UV CD spectroscopic analysis points toward an enhanced beta-sheet structure of the pGlu-Abeta. Importantly, changes in fibril morphology are clearly caused by the N-terminal pGlu, resulting in the formation of short fibers, which are frequently arranged in bundles. The effect of pGlu on the morphology is virtually indistinguishable between ABri, ADan, and Abeta. The data provide evidence for a comparable influence of the pGlu modification on the aggregation process of structurally different amyloid peptides, thus likely contributing to the molecularly distinct neurodegenerative diseases AD, FBD, and FDD. The main driving force for the aggregation is apparently an increase in the hydrophobicity and thus an accelerated seed formation.

Employment across chronic inflammatory rheumatic diseases and comparison with the general population.

Abstract: OBJECTIVE: To compare labor force participation across chronic inflammatory rheumatic diseases in order to assess the influence of the disease, disease duration, sex, education, and labor market conditions on employment. METHODS: Data from the German rheumatological database on outpatients of working age (20-59 yrs) between 1993 and 2001 were analyzed. The patients had rheumatoid arthritis (RA; n = 26,071), ankylosing spondylitis (AS; n = 5564), psoriatic arthritis (PsA; n = 6041), systemic lupus erythematosus (SLE; n = 4603), systemic sclerosis (SSc; n = 802), or Wegener9s granulomatosis (WG; n = 385). Using population data, standardized employment ratios (SER) and part-time employment ratios of observed versus expected cases with 95% CI were calculated by means of indirect standardization for age and year of documentation. RESULTS: Across all diseases the overall employment rates were significantly lower than in the general population. Significant differences in SER were found between the diseases. The lowest SER of 0.76 to 0.81 (1.0 = population) were found in patients with RA, SLE, SSc, and WG. Higher SER were seen in AS (0.94) and PsA (0.92). In patients with a disease duration > 10 years the relative risk of being employed compared to RA, was 1.42 for AS, 1.26 for PsA, and 1.15, 1.03, 0.62 for PsA, SLE, SSc and WG, respectively. Comparing areas with low and high unemployment rates, a highly significant influence of labor market conditions on the SER was observed. The SER were significantly lower in patients with

A critical assessment of micellization of sodium dodecyl benzene sulfonate (SDBS) and its interaction with poly(vinyl pyrrolidone) and hydrophobically modified polymers, JR 400 and LM 200

Abstract: The self-aggregation of sodium dodecyl benzene sulfonate (SDBS) and its solution behaviors have been critically assessed by conductometric, tensiometric, spectrophotometric, flourimetric, and calorimetric methods. The interfacial adsorption behaviors of SDBS have also been assessed critically. Based on the isothermal titration calorimetric (ITC) measurements, the thermodynamics of micellization of SDBS have been examined in the light of both “mass action” and “pseudophase” principles. A method of simulation has been used to evaluate the aggregation number and the free energy of micellization according to the mass action model. The thermodynamic parameters derived indirectly from the rationale of van't Hoff and directly by microcalorimetry have been compared and discussed. The interaction of SDBS with the water-soluble polymers poly(vinyl pyrrolidone) (PVP), the chloride salt of the N,N-dimethyl-N-methyl derivative of hydroxyethylcellulose (JR 400), and the chloride salt of the N,N-dimethyl-N-dodecyl deriv...