Effect of fluoropolymer antidripping agent on rheological behavior of LLDPE

In this work, high molecular weight polytetrafluoroethylene based antidripping agent was blended with Ziegler-Natta based LLDPE in different concentrations. Rheological characterization was consequently performed for all the blends and the obtained results were compared with the pure LLDPE. It has been found that high molecular weight PTFE based melt modifier MM 5935 EF significantly enhancing the shear viscosity/elasticity and especially the extensional viscosity of the LLDPE melt. © 2011 American Institute of Physics

Long-term outcomes from the Phase II L-MIND study of tafasitamab (MOR208) plus lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma

Tafasitamab (MOR208), an Fc-modified, humanized, anti-CD19 monoclonal antibody, combined with the immunomodulatory drug lenalidomide was clinically active with a good tolerability profile in the open-label, single-arm, phase II L-MIND study of patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) ineligible for autologous stem-cell transplantation. To assess long-term outcomes, we report an updated analysis with ≥35 months' follow-up. Patients were aged >18 years, had received one to three prior systemic therapies (including ≥1 CD20-targeting regimen) and Eastern Cooperative Oncology Group performance status 0-2. Patients received 28-day cycles of tafasitamab (12 mg/kg intravenously), once weekly during cycles 1-3, then every 2 weeks during cycles 4-12. Lenalidomide (25 mg orally) was administered on days 1-21 of cycles 1-12. After cycle 12, progression-free patients received tafasitamab every 2 weeks until disease progression. The primary endpoint was best objective response rate. After ≥35 months' follow-up (data cut-off: October 30, 2020), the objective response rate was 57.5% (n=46/80), including a complete response in 40.0% of patients (n=32/80) and a partial response in 17.5% of patients (n=14/80). The median duration of response was 43.9 months (95% confidence interval [95% CI]: 26.1-not reached), the median overall survival was 33.5 months (95% CI: 18.3-not reached) and the median progression-free survival was 11.6 months (95% CI: 6.3-45.7). There were no unexpected toxicities. Subgroup analyses revealed consistent long-term efficacy results across most subgroups of patients. This extended follow-up of L-MIND confirms the long duration of response, meaningful overall survival, and well-defined safety profile of tafasitamab plus lenalidomide followed by tafasitamab monotherapy in patients with relapsed/refractory diffuse large B-cell lymphoma ineligible for autologous stem cell transplantation. ClinicalTrials.gov identifier: NCT02399085

Investigation of crosslinking behaviour of silane grafted polyethylene through rheology

In this work the crosslinking behaviour of two silane-grafted polyethylenes was investigated with respect to time and temperature by using dynamic rheological measurements. It has been found that inhomogeneous character of the crosslinking reaction takes place in both tested samples. By utilization of G′-G" crossover method, it has been found that the sample with initially distinct crosslinking state and short critical crosslinking reaction time has high tendency to create small gels during production of hot water pipes. It has also been revealed that the temperature dependence of the critical time, at which the crosslinking speed is the highest, shows an Arrhenius-type behaviour. © 2013 AIP Publishing LLC

Group I PAK Inhibitor IPA-3 Induces Cell Death and Affects Cell Adhesivity to Fibronectin in Human Hematopoietic Cells

<div><p>P21-activated kinases (PAKs) are involved in the regulation of multiple processes including cell proliferation, adhesion and migration. However, the current knowledge about their function is mainly based on results obtained in adherent cell types. We investigated the effect of group I PAK inhibition using the compound IPA-3 in a variety of human leukemic cell lines (JURL-MK1, MOLM-7, K562, CML-T1, HL-60, Karpas-299, Jurkat, HEL) as well as in primary blood cells. IPA-3 induced cell death with EC50 ranging from 5 to more than 20 μM. Similar range was found for IPA-3-mediated dephosphorylation of a known PAK downstream effector, cofilin. The cell death was associated with caspase-3 activation, PARP cleavage and apoptotic DNA fragmentation. In parallel, 20 μM IPA-3 treatment induced rapid and marked decrease of the cell adhesivity to fibronectin. Per contra, partial reduction of PAK activity using lower dose IPA-3 or siRNA resulted in a slight increase in the cell adhesivity. The changes in the cell adhesivity were also studied using real-time microimpedance measurement and by interference reflection microscopy. Significant differences in the intracellular IPA-3 level among various cell lines were observed indicating that an active mechanism is involved in IPA-3 transport.</p></div

Adhesion structures in leukemia cells and their regulation by Src family kinases

<p>Interaction of leukemia blasts with the bone marrow extracellular matrix often results in protection of leukemia cells from chemotherapy and in persistence of the residual disease which is on the basis of subsequent relapses. The adhesion signaling pathways have been extensively studied in adherent cells as well as in mature haematopoietic cells, but the adhesion structures and signaling in haematopoietic stem and progenitor cells, either normal or malignant, are much less explored. We analyzed the interaction of leukemia cells with fibronectin (FN) using interference reflection microscopy, immunofluorescence, measurement of adherent cell fraction, real-time microimpedance measurement and live cell imaging. We found that leukemia cells form very dynamic adhesion structures similar to early stages of focal adhesions. In contrast to adherent cells, where Src family kinases (SFK) belong to important regulators of focal adhesion dynamics, we observed only minor effects of SFK inhibitor dasatinib on leukemia cell binding to FN. The relatively weak involvement of SFK in adhesion structure regulation might be associated with the lack of cytoskeletal mechanical tension in leukemia cells. On the other hand, active Lyn kinase was found to specifically localize to leukemia cell adhesion structures and a less firm cell attachment to FN was often associated with higher Lyn activity (this unexpectedly occurred also after cell treatment with the inhibitor SKI-1). Lyn thus may be important for signaling from integrin-associated complexes to other processes in leukemia cells.</p

Expression of PAK kinases in the studied cell lines.

<p>Cell proteins were separated using gel electrophoresis and the expression levels of PAK1, PAK2, phospho-PAK (Ser 144/Ser141) and phospho-PAK2 (Ser20) were determined using western-blotting. (A) Lanes 1–8 correspond to the individual cell lines: (1) JURL-MK1, (2) MOLM-7, (3) K562, (4) CML-T1, (5) HL60, (6) Karpas-299, (7) Jurkat, (8) HEL. (B) CML-T1 cells were treated with IPA-3 at the indicated concetrations for 2 h, then lysed and subjected to electrophoresis and western-blotting. (C) Relative expression levels of phospho-PAK2 (Ser141) and PAK2 in cell lines treated for 2 h with IPA-3 at different concentrations. The band intensity from western-blots with anti-PAK antibodies was corrected for small differencies in protein loads using actin bands and the resulting values were expressed as relative to controls (without treatment). JURL-MK1:closed circles, MOLM-7:closed triangles, CML-T1:closed squares, K562:open circles, HL60:open squares, JURKAT:open triangles, Karpas-299:open diamonds, HEL:closed diamonds.</p

Intracellular IPA-3 amount determined using flow cytometry or fluorescence spectroscopy.

<p>(A, B) Results from flow cytometry measurements. The relative amount of IPA-3 was obtained as the increase in the mean fluorescence intensity (MFI) at 405/450 nm (excitation/emission) from samples incubated for 1 h with IPA-3 at 5, 10 or 20 μM extracellular concentration (white, light grey and dark grey bars, respectively) compared to the untreated control samples. (A) Cells were seeded at 2×10⁵ cells/ml, the figure shows means and standard deviations from 3 independent experiments. (B) JURL-MK1 cells were seeded at different cell density as indicated and incubated for 1 h with IPA-3. (C) MOLM-7 cells were seeded at 6×10⁵ (dotted line) or 1×10⁵ cells/ml (solid line) and incubated for 1 h with 20 μM IPA-3 (extracellular concentration). Cell aliquots (6×10⁵ cells from each sample) were lyzed and suspended in DMSO and fluorescence spectra were recorded with the excitation wavelength set to 405 nm. The background fluorescence (sample from the same amount of untreated cells) was subtracted. Closely similar results were obtained in repeated experiments.</p

Effect of IPA-3 on HEL cell interaction with fibronectin-coated surface.

<p>(A) HEL cells (at 1×10⁵ cells/ml) were pretreated for 30 min with 20 μM IPA-3 and the same amount (60 000) of control (blue) and IPA-3-treated (red) cells was applied to FN-coated microplate with embedded microelectrodes. The observed changes in microimpedance reflect cell binding to the cell bottom. (B) HEL cells (20 000/well) were applied to FN-coated microplate and allowed to adhere for about 90 min. Then IPA-3 was added at the time point indicated by the arrow. Blue: DMSO only, red: IPA-3 (20 μM final concentration in the well). Curves in A and B show means and standard deviations of wells in quadruplicates. (C) Analysis of HEL cells interacting with FN-coated coverslips by interference reflection microscopy. The cells were pretreated with 20 μM IPA-3 (right panel) or left untreated (left panel) prior to incubation for 1 h on FN-coated coverslip (at 37°C). Scale bars: 10 μm. (D) Comparison of cell areas for control and IPA-3-treated HEL cells. The experiment was performed as in (C) and the cell area was measured for about 250 cells (all cells in multiple randomly chosen fields).</p

Summary of results obtained for the individual leukemic cell lines treated with 20 μM IPA-3.

<p>The protein expression, intracellular IPA-3 content and cell response to treatment were classified as low (+), medium (++) or high (+++) with regard to the range of the observed values from the whole set of cell lines. To assess IPA-3 intracellular concentration, the measured values for mean fluorescence intensity (shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092560#pone-0092560-g003" target="_blank">Fig. 3A</a>) were corrected for differences in the cell volume estimated from the measured cell diameter.</p

Effect of IPA-3 on cofilin phosphorylation at Ser3.

<p>Cells were incubated for 2 μM IPA-3 (white bars and dark bars, respectively), lysed and the level of cofilin and phospho-cofilin (Ser3) was determined by western-blotting. The level of total cofilin remained essentially unchanged and was used as the loading control. Phospho-cofilin/cofilin ratio was expressed as relative to the value obtained from untreated controls (100%). The graph shows means and standard deviations from repeated independent experiments.</p