Protective Effects of a Hyaluronan-Binding Peptide (P15-1) on Mesenchymal Stem Cells in an Inflammatory Environment

Mesenchymal stem cells (MSCs) obtained from various sources, including bone marrow, have been proposed as a therapeutic strategy for the improvement of tissue repair/regeneration, including the repair of cartilage defects or lesions. Often the highly inflammatory environment after injury or during diseases, however, greatly diminishes the therapeutic and reparative effectiveness of MSCs. Therefore, the identification of novel factors that can protect MSCs against an inflammatory environment may enhance the effectiveness of these cells in repairing tissues, such as articular cartilage. In this study, we investigated whether a peptide (P15-1) that binds to hyaluronan (HA), a major component of the extracellular matrix of cartilage, protects bone-marrow-derived MSCs (BMSCs) in an inflammatory environment. The results showed that P15-1 reduced the mRNA levels of catabolic and inflammatory markers in interleukin-1beta (IL-1β)-treated human BMSCs. In addition, P15-1 enhanced the attachment of BMSCs to HA-coated tissue culture dishes and stimulated the chondrogenic differentiation of the multipotential murine C3H/10T1/2 MSC line in a micromass culture. In conclusion, our findings suggest that P15-1 may increase the capacity of BMSCs to repair cartilage via the protection of these cells in an inflammatory environment and the stimulation of their attachment to an HA-containing matrix and chondrogenic differentiation.     

Isolation of Decidual Macrophages and Hofbauer Cells from Term Placenta—Comparison of the Expression of CD163 and CD80

(1) Background: Placental immune cells are playing a very important role in a successful placentation and the prevention of pregnancy complications. Macrophages dominate in number and relevance in the maternal and the fetal part of the placenta. The evidence on the polarization state of fetal and maternal macrophages involved in both, healthy and pregnancy-associated diseases, is limited. There is no representative isolation method for the direct comparison of maternal and fetal macrophages so far. (2) Material and Methods: For the isolation of decidual macrophages and Hofbauer cells from term placenta, fresh tissue was mechanically dissected and digested with trypsin and collagenase A. Afterwards cell enrichment was increased by a Percoll gradient. CD68 is represented as pan-macrophage marker, the surface markers CD80 and CD163 were further investigated. (3) Results: The established method revealed a high cell yield and purity of the isolated macrophages and enabled the comparison between decidual macrophages and Hofbauer cells. No significant difference was observed in the percentage of single CD163⁺ cells in the distinct macrophage populations, by using FACS and immunofluorescence staining. A slight increase of CD80⁺ cells could be found in the decidual macrophages. Considering the percentage of CD80⁺CD163⁻ and CD80⁻CD163⁺ cells we could not find differences. Interestingly we found an increased number of double positive cells (CD80⁺CD163⁺) in the decidual macrophage population in comparison to Hofbauer cells. (4) Conclusion: In this study we demonstrate that our established isolation method enables the investigation of decidual macrophages and Hofbauer cells in the placenta. It represents a promising method for direct cell comparison, enzyme independently, and unaffected by magnetic beads, to understand the functional subsets of placental macrophages and to identify therapeutic targets of pregnancy associated diseases.     

Response of Multiwire Proportional Chambers to Relativistic Heavy Nuclei

Measurements have been carried out at the Lawrence Berkeley Laboratory Bevatron to investigate the response of multiwire proportional chambers to 2. 1 GeV/nucleon C12 and O16 nuclei. The relative gas gain as a function of high voltage was measured for three different gases: 80% Ar/20%CO2, 75% Ar/ 25%C4H10, and 81% Ar/14% Xe/5%CO2. The gas gain obtained with 5.9 KeV X-rays from Fe55 sources was also measured for comparison. Saturation characteristics of the chambers are analyzed and the implications of the results on the use of multiwire proportional chambers as spatial detectors in cosmic ray experiments are discussed. A summary of the results of delta ray calculations and their effect on spatial resolution is also presented.     

Base-compositional biases and the bat problem. II. DNA-hybridization trees based on AT- and GC-enriched tracers

We conducted a series of parallel DNA-hybridization experiments on a small group of bats (species of Pteropus, Rhinolophus, Noctilio and Pteronotus) and outgroups (Lemur, Cynocephalus, Didelphis), using whole-genome labels and tracers made from extracts enriched with AT and two levels of GC content. FITCH (additive phylogenetic trees) topologies were constructed from the four sets of comparisons, indexed as both delta Tmode and delta NPHs (normalized percentage of hybridization). Based on our previous work showing that the shared AT bias of pteropodids and some microchiropterans may affect the rank-ordering of taxa based on either AT- or GC-rich labels, our expectation was that the resulting trees would show differing topologies when generated from tracers made with the variously enriched DNA extracts. Whereas there was some variation among the trees, most of them grouped the bats together, and almost all paired the representative megachiropteran and rhinolophoid microchiropteran as sister-taxa in contrast to the other microchiropterans. As the pteropodid-rhinolophoid relationship is an unexpected and unlikely one, we attribute this association to an AT bias that was not obviated even by our most GC-rich labels, and suggest that such a bias may compromise the truth of some molecular trees. Accordingly, we believe the broader issue of bat monophyly remains unresolved by DNA-hybridization and probably also by gene-sequencing studies.     

Electrochemical oxidation analysis for dressing bronze-bonded diamond grinding wheels

Electrochemical dressing of fine-grained metal-bonded diamond grinding wheels enables to grind hard and brittle materials in the ductile mode. Optical surfaces can be manufactured by grinding, which reduces the need for subsequent, time-consuming polishing work. When using metal-bonded grinding wheels, the emerging oxides regulate the electrochemical dissolution. Bronze-bonded grinding wheels are more suitable for grinding cemented carbides and ceramics than iron-bonded grinding wheels, as it is easier to modify their chemical composition to suit a specific grinding task. They can also be sintered at lower temperatures, which reduces the risk of thermal damage to the diamond. In this paper, the dissolution and the oxidation of different bronze alloys are characterized for the electrochemical dressing process. The relevant evaluation criteria are the oxide layer thickness, the electrical behavior and the different emerging bronze alloy oxides. This work is funded by the German Research Association DFG within the Transregional Collaborative Research Center SFB/TR4 “Process Chains for the Replication of Complex Optical Elements”.     

Kinetik der aeroben Abwasserreinigung durch Abbau von organischen Verbindungen und durch Nitrifikation

Kinetics of aerobic waste water treatment by degrading organic compounds and by nitrification . Both aerobic degradation of organic substances and nitrification can be described by the double substrate kinetics of Monod; dissolved organic material and ammonium or nitrite are the first substrate and oxygen the second one. The determination of the different kinetic coefficients by evaluation of measurements on a laboratory scale is explained first, and known results are then presented and discussed. Finally, it is demonstrated by two examples, viz. the simultaneous oxidation of carbon and nitrogen compounds and oxygen-limited substrate removal, how reaction kinetic models can be used to obtain important information about the characteristics of the bioreactions.