Synchronized turbo apoptosis induced by cold-shock

In our research on the role of apoptosis in the pathogenesis of the autoimmune disease systemic lupus erythematosus (SLE), we aim to evaluate the effects of early and late apoptotic cells and blebs on antigen presenting cells. This requires the in vitro generation of sufficiently large and homogeneous populations of early and late apoptotic cells. Here, we present a quick method encountered by serendipity that results in highly reproducible synchronized homogeneous apoptotic cell populations. In brief, granulocytic 32Dcl3 cells are incubated on ice for 2 h and subsequently rewarmed at 37°C. After 30–90 min at 37°C more than 80–90% of the cells become early apoptotic (Annexin V positive/propidium iodide negative). After 24 h of rewarming at 37°C 98% of the cells were late apoptotic (secondary necrotic; Annexin V positive/propidium iodide positive). Cells already formed apoptotic blebs at their cell surface after approximately 20 min at 37°C. Inter-nucleosomal chromatin cleavage and caspase activation were other characteristics of this cold-shock-induced process of apoptosis. Consequently, apoptosis could be inhibited by a caspase inhibitor. Finally, SLE-derived anti-chromatin autoantibodies showed a high affinity for apoptotic blebs generated by cold-shock. Overall, cold-shock induced apoptosis is achieved without the addition of toxic compounds or antibodies, and quickly leads to synchronized homogeneous apoptotic cell populations, which can be applied for various research questions addressing apoptosis

Моделирование диффузии водорода по границам зерен в титане

В результате исследования было определено, что коэффициенты диффузии, полученные методом молекулярной динамики, подчиняются уравнению Аррениуса, т.е. с ростом температуры увеличивается и коэффициенты диффузии. Результаты расчетов согласуются с экспериментальными данными и другими расчетами. Результаты исследований могут быть полезны для исследователей, изучающих системы металл-водород, а также в области материаловедения, авиаконструкция и водородной энергетики. Кроме того, для теоретиков, работающих в области молекулярно-динамических расчетов, данные расчеты позволят оценить границы применимости используемого потенциала взаимодействия.As a result of the study, it was determined that the diffusion coefficients obtained by the molecular dynamics method obey the Arrhenius equation, i.e. With increasing temperature, the diffusion coefficients also increase. The results of the calculations are consistent with the experimental data and other calculations. The results of the research can be useful for researchers studying metal-hydrogen systems, as well as in the field of materials science, aircraft construction and hydrogen energy. In addition, for theorists working in the field of molecular dynamics calculations, these calculations will make it possible to estimate the limits of applicability of the interaction potential use

HT2005-72679 THERMAL CHARACTERIZATION OF DIELECTRIC AND PHASE CHANGE MATERIALS FOR THE OPTICAL RECORDING APPLICATIONS

Abstract Advances in the phase change optical recording technology strongly depend on the optical and thermal optimizations of the metal/ZnS-SiO 2 /phase change multilayer structure, which requires accurate modeling and thermal characterization of PC media structure. In the present work, the thermal conductivities of the amorphous and crystalline Ge 4 Sb 1 Te 5 (GST) phase change; and ZnS-SiO 2 dielectric layers of thickness in the range of 50 nm to 300 nm have been measured using the transient thermoreflectance technique. The data are between a factor of 2-4 different from the previously measured values for thin film and bulk samples. The thermal boundary resistance at metal/ZnS-SiO 2 interface is found to be around 7×10 -8 m 2 W -l . This might have serious implications for the future phase change recording application which attempts to achieve the high writing speeds by decreasing the thickness of ZnS-SiO 2 dielectric layer

Changes in Electronic Structure and Chemical Bonding upon Crystallization of the Phase Change Material GeSb₂Te₄

High-resolution photoelectron spectroscopy of in situ prepared films of GeSb₂Te₄ reveals significant differences in electronic and chemical structure between the amorphous and the crystalline phase. Evidence for two different chemical environments of Ge and Sb in the amorphous structure is found. This observation can explain the pronounced property contrast between both phases and provides new insight into the formation of the amorphous state

Reactivity in ELISA with DNA-loaded nucleosomes in patients with proliferative lupus nephritis

Item does not contain fulltextAutoantibodies against nucleosomes are considered a hallmark of systemic lupus erythematosus (SLE). We compared in patients with proliferative lupus nephritis the diagnostic usefulness of a dsDNA-loaded nucleosome ELISA (anti-dsDNA-NcX) with ELISAs in which dsDNA or nucleosomes alone were coated. First, we analysed whether DNA loading on nucleosomes led to masking of epitopes by using defined monoclonal anti-DNA, anti-histone and nucleosome-specific autoantibodies to evaluate the accessibility of nucleosomal epitopes in the anti-dsDNA-NcX ELISA. Second, autoantibody levels were measured in these 3 ELISAs in 100 patients with proliferative lupus nephritis (LN) before immunosuppressive treatment and in 128 non-SLE disease controls. In patients with LN inter-assay comparisons and associations with clinical and serological parameters were analysed. The panel of monoclonal antibodies revealed that all epitopes were equally accessible in the anti-dsDNA-NcX ELISA as in the two other ELISAs. Patients with proliferative lupus nephritis were positive with dsDNA-loaded nucleosomes in 86%, with DNA in 66% and with nucleosomes in 85%. In the non-lupus disease control group these frequencies were 1.6% (2 out of 128) for both the anti-dsDNA-NcX and the anti-dsDNA ELISA and 0% in the anti-nucleosome ELISA. The levels in the anti-dsDNA-NcX ELISA were high in a group of patients with LN that showed absent reactivity in the anti-DNA or low levels in the anti-nucleosome ELISA. Anti-dsDNA-NcX positivity was associated with higher SLEDAI scores within this group. Within nucleosome-based ELISAs, we propose the anti-dsDNA-NcX ELISA as the preferred test system

Isoforms of U1-70k control subunit dynamics in the human spliceosomal U1 snRNP

Most human protein-encoding genes contain multiple exons that are spliced together, frequently in alternative arrangements, by the spliceosome. It is established that U1 snRNP is an essential component of the spliceosome, in human consisting of RNA and ten proteins, several of which are post- translationally modified and exist as multiple isoforms. Unresolved and challenging to investigate are the effects of these post translational modifications on the dynamics, interactions and stability of the particle. Using mass spectrometry we investigate the composition and dynamics of the native human U1 snRNP and compare native and recombinant complexes to isolate the effects of various subunits and isoforms on the overall stability. Our data reveal differential incorporation of four protein isoforms and dynamic interactions of subunits U1-A, U1-C and Sm-B/B’. Results also show that unstructured post- ranslationally modified C-terminal tails are responsible for the dynamics of Sm-B/B’ and U1-C and that their interactions with the Sm core are controlled by binding to different U1-70k isoforms and their phosphorylation status in vivo. These results therefore provide the important functional link between proteomics and structure as well as insight into the dynamic quaternary structure of the native U1 snRNP important for its function.This work was funded by: BBSRC (OVM), BBSRC and EPSRC (HH and NM), EU Prospects (HH), European Science Foundation (NM), the Royal Society (CVR), and fellowship from JSPS and HFSP (YM and DAPK respectively)