p100: a novel proliferation-associated nuclear protein specifically restricted to cell cycle phases S, G2, and M

By immunization with nuclear lysates of L428 cells, we raised a monoclonal mouse antibody, Ki-S2 (IgG1). In Western blots, this antibody recognizes a nuclear antigen with an apparent molecular mass of 100 kD, termed p100. Protein sequencing of p100 showed that this is a hitherto unknown protein. Immunohistochemical examination of cryostat and paraffin sections of nearly all human tissue types and neoplasms showed that p100 was exclusively expressed in the nuclei of a fraction of proliferating cells. Cell sorting and fluorescence-activated cell sorting analysis of stimulated peripheral blood mononuclear cells showed that p100 was exclusively expressed in proliferating cells from the transition G1/S until the end of cytokinesis. During mitosis, this protein is strictly associated with the spindle pole and with the mitotic spindle, whereas during S and G2, p100 is diffusely distributed throughout the cell nucleus. Immediately after completion of cytokinesis, p100 was rapidly degraded. In L428 cells, p100 is phosphorylated at least during mitosis. It has a turnover time of about 1 hour. Studies on routinely processed paraffin sections of specimens of malignant lymphoma, benign and malignant nevocellular tumors, and breast cancer showed that in all cases less than 40% of the Ki-67-positive growth fraction expressed p100. Thus, p100 might prove to be a more reliable measure of cellular proliferation and one that is more closely correlated to cancer prognosis, beyond its general biologic relevance as a cell cycle protein.     

Psychologists in service to science: The American Psychological Association and the American Association for the Advancement of Science.

The American Association for the Advancement of Science (AAAS) celebrates its 150th anniversary in 1998. The American Psychological Association and the AAAS have been linked institutionally since the early part of this century, and 3 psychologists in particular have been prominent figures in the AAAS at critical times in its history. James McKeen Cattell revived the journal Science, orchestrated its link to the AAAS, and helped strengthen the AAAS's ties to its affiliated organizations; Dael Wolfle was instrumental in transforming the AAAS into a professional organization with a variety of public programs; and William Bevan helped the AAAS to weather the turbulent years of the early 1970s, stressing the importance of scientists' responsibility to society. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biochemical analysis of torso and D-raf during Drosophila embryogenesis: implications for terminal signal transduction

Determination of anterior and posterior terminal structures of Drosophila embryos requires activation of two genes encoding putative protein kinases, torso and D-raf. In this study, we demonstrate that Torso has intrinsic tyrosine kinase activity and show that it is transiently tyrosine phosphorylated (activated) at syncytial blastoderm stages. Torso proteins causing a gain-of-function phenotype are constitutively tyrosine phosphorylated, while Torso proteins causing a loss-of-function phenotype lack tyrosine kinase activity. The D-raf gene product, which is required for Torso function, is identified as a 90-kDa protein with intrinsic serine/threonine kinase activity. D-Raf is expressed throughout embryogenesis; however, the phosphorylation state of the protein changes during development. In wild-type embryos, D-Raf is hyperphosphorylated at 1 to 2 h after egg laying, and thereafter only the most highly phosphorylated form is detected. Embryos lacking Torso activity, however, show significant reductions in D-Raf protein expression rather than major alterations in the protein's phosphorylation state. This report provides the first biochemical analysis of the terminal signal transduction pathway in Drosophila embryos.     

Study of the orientational electric field effect in 3He-B

We have studied the orienting effect that an electric field has on the orbital motion of the pairs in superfluid ³He-B, using the orientation-dependent transverse NMR frequency shift as a probe. This method provides high resolution for studying the orienting effect for either sign of the orientational energy. Electric fields as high as 35,000 V/cm applied across the sample produced no measurable frequency shift at 0-, 10-, and 32-bar pressures. This gives upper limits to the orientational energy of 1.4 × 10^\s-3, 1.0 × 10^\s-3 and 4 × 10^\s-4 times the values expected from simple theory.     

No evidence for cerium dioxide nanoparticle translocation in maize plants

The rapidly increasing production of engineered nanoparticles has raised questions regarding their environmental impact and their mobility to overcome biological important barriers. Nanoparticles were found to cross different mammalian barriers, which is summarized under the term translocation. The present work investigates the uptake and translocation of cerium dioxide nanoparticles into maize plants as one of the major agricultural crops. Nanoparticles were exposed either as aerosol or as suspension. Our study demonstrates that 50 μg of cerium/g of leaves was either adsorbed or incorporated into maize leaves. This amount could not be removed by a washing step and did not depend on closed or open stomata investigated under dark and light exposure conditions. However, no translocation into newly grown leaves was found when cultivating the maize plants after airborne particle exposure. The use of inductively coupled mass spectrometer allowed detection limits of less than 1 ng of cerium/g of leaf. Exposure of plants to well-characterized nanoparticle suspensions in the irrigation water resulted also in no detectable translocation. These findings may indicate that the biological barriers of plants are more resistant against nanoparticle translocation than mammalian barriers.     

Keramische Membranen: Materialien – Bauteile – potenzielle Anwendungen

Ceramic membranes can be divided into dense and porous membranes. The materials, microstructure, and manufacturing methods are described and insights into current research topics are given. By adapting the material properties and tailoring microstructures, membranes and components suitable for a variety of processes can be developed. In applications, a distinction can be made between pure gas separation and membrane reactors. In the latter ones, in addition to gas separation, a chemical reaction takes place on one or both sides of the membrane. Membrane reactors can be used to produce basic chemicals or synthetic fuels. The supply of gases can be of interest for power plants, cement, steel or glassworks as well as for the medical sector or for mobile applications.     

Length-dependent DNA degradation kinetic model: Decay compensation in DNA tracer concentration measurements

DNA is often used as a tracer in both environmental fluid flow characterization and in material tracking to avoid counterfeiting and ensure transparency in product value chains. The main drawback of DNA as a tracer is its limited stability, making quantitative analysis difficult. Here, we study length-dependent DNA decay at elevated temperatures and under sunlight by quantitative PCR and show that the stability of randomly generated DNA sequences is inversely proportional to the sequence length. By quantifying the remaining DNA length distribution, we present a method to determine the extent of decay and to account for it. We propose a correction factor based on the ratio of measured concentrations of two different length sequences. Multiplying the measured DNA concentration by this length-dependent correction factor enables precise DNA tracer quantification, even if DNA molecules have undergone more than 100-fold degradation. © 2018 American Institute of Chemical Engineers AIChE J, 65: 40–48, 2019     

Exposure of aerosols and nanoparticle dispersions to in vitro cell cultures: A review on the dose relevance of size, mass, surface and concentration

The exposure of cell cultures to aerosols or nanoparticle dispersions offers an experimental access to study particle related toxicology and nanomedicine. The present article discusses the concept of dose for soluble or persistent particles with optional stabilizing shells and/or chemical or catalytic activity. We further investigate the minimal set of experiments and controls required for hands-on experiments feasible in well-equipped standard research laboratories. This article recommends strategies to implement nanotoxicity experiments into laboratory routine and shall assist aerosol scientists to engage into biological/medical questions. The most prominent differences between molecule- and particle-related health effects are additionally discussed as physical (concentration-dependent mobility due to agglomeration) and chemical effects (catalytic/chemically active surfaces, Trojan horse type toxin transport through membranes, long-term risks). In the last part we describe the implementation of these concepts within the Swiss Recommendations for Industrial Use of Nanoparticles as a first attempt to provide a regulatory framework for the risk assessment of nanoproducts.