Search

(Leukaemia derived) dendritic cells (DC, DC leu ) are potent stimulators of anti-leukaemic activity in acute myeloid leukaemia (AML) and can be generated with immunomodulatory kits containing granulocyte-macrophage-colony-stimulating-factor (GM-CSF), prostaglandin-E 1 (PGE 1 ), prostaglandin-E 2 (PGE 2 ) and/or picibanil (OK-321). Potential adverse effects initiated through kits, especially the proliferation of blasts, must be ruled out to ensure treatment safety. We quantified proliferating blasts with the proliferation markers CD71 and Ki-67 and the novel proliferation marker IPO-38 before and after kit treatment ex vivo. IPO-38 hereby appeared to be the most sensitive marker; a combination with CD71 may add value when assessing proliferation kinetics. Kit treatment did not or only slightly (<5%) induce blast proliferation in most cases. An induction of blast proliferation was only found in single cases and could be compensated by DC leu -induced anti-leukaemic activity in most times. Overall, we appraise kit treatment to be safe in vivo., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Modiblast Pharma GmbH (Oberhaching, Germany) holds the European Patent 15,801,987.7–1118 and US Patent 15–517,627 “Use of immunomodulatory effective compositions for the immunotherapeutic treatment of patients suffering from myeloid leukemias”, in which Helga Maria Schmetzer is involved., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Fast transient fluorescence technique was used to monitor swelling of hard latex particles in a soft polymer matrix. Various film samples were prepared from pyrene (P) and/or naphthalene (N)-labeled poly(methyl methacrylate) (PMMA) particles in a low-molecular-weight poly(isobutylene) (PIB) matrix. These PMMA particles contain interpenetrating PIB channels. Film samples were annealed at elevated temperatures to promote particle swelling. Fluorescence lifetimes, tau, were measured for each film sample. It was observed that tau values decrease as the PIB content in the matrix is increased. The decrease in tau was explained by the increase in quenching of excited P and N molecules by low-molecular-weight PIB penetrating into the PIB channels in the PMMA particles. A drastic decrease in tau above a certain temperature was attributed to the effect of particle size on the swelling of the latex particles in the PIB matrix. It was observed that small particles (P-labeled) swell at much lower annealing temperatures than large (N-labeled) particles.

Latex films have been prepared by annealing pyrene (Py)-labeled poly(methyl methacrylate)-polyisobutylene particles at the glass transition temperature (100 degrees C). These films were then irradiated by gamma rays from (60)Co in a gamma cell at room temperature at various dose rates (rad/h). Before dissolution the films were annealed at 200 degrees C for a 30 min time interval to complete the film formation process. Steady-state fluorescence techniques were used to monitor the dissolution of irradiated latex films. Dissolution of films in a chloroform-heptane (80%-20%) mixture was monitored in real time by the Py fluorescence intensity change. Relaxation constants, k(0), and dissolution coefficients, D(d), of polymer chains were measured. Two different regimes of D(d) values were observed during dissolution, which are related to two different molecular weight distributions caused by scission and branching of polymer chains when they were irradiated and annealed. Copyright 2001 Academic Press.