47 research outputs found
A Natural Combination Extract of Viscum album L. Containing Both Triterpene Acids and Lectins Is Highly Effective against AML In Vivo
Aqueous Viscum album L. extracts are widely used in complementary cancer
medicine. Hydrophobic triterpene acids also possess anti-cancer properties,
but due to their low solubility they do not occur in significant amounts in
aqueous extracts. Using cyclodextrins we solubilised mistletoe triterpenes
(mainly oleanolic acid) and investigated the effect of a mistletoe whole plant
extract on human acute myeloid leukaemia cells in vitro, ex vivo and in vivo.
Single Viscum album L. extracts containing only solubilised triterpene acids
(TT) or lectins (viscum) inhibited cell proliferation and induced apoptosis in
a dose-dependent manner in vitro and ex vivo. The combination of viscum and TT
extracts (viscumTT) enhanced the induction of apoptosis synergistically. The
experiments demonstrated that all three extracts are able to induce apoptosis
via caspase-8 and -9 dependent pathways with down-regulation of members of the
inhibitor of apoptosis and Bcl-2 families of proteins. Finally, the acute
myeloid leukaemia mouse model experiment confirmed the therapeutic
effectiveness of viscumTT-treatment resulting in significant tumour weight
reduction, comparable to the effect in cytarabine-treated mice. These results
suggest that the combination viscumTT may have a potential therapeutic value
for the treatment AML
Towards integration of glass microlens with silicon comb-drive X-Y microstage
International audienc
Silicon comb-drive X-Y microstage with frame-in-the-frame architecture for MOEMS applications
International audienceIn this paper we present the silicon comb-drive X-Y microstage with the frame-in-the-frame architecture intended to be monolithically integrated with a glass microlens as a MOEMS 2D scanner for the Miniaturized Confocal Microscope On-Chip. The microstage is characterized by relatively large travel range (± 35 μm in X-direction and ± 28 μm in Y-direction at 100 V) for a small number of driving electrodes, without noticeable mechanical X-Y crosstalk. We describe the design, ANSYS modeling, fabrication process and static characterization of the device
Flexible function block for industrial applications of active disturbance rejection controller
In this paper, the PLC-based (Programmable Logic Controller) industrial implementation
in the form of the general-purpose function block for ADRC (Active Disturbance Rejection
Controller) is presented. The details of practical aspects are discussed because their reliable
implementation is not trivial for higher order ADRC. Additional important novelties discussed
in the paper are the impact of the derivative backoff and the method that significantly simplifies
tuning of higher order ADRC by avoiding the usual trial and error procedure. The results of
the practical validation of the suggested concepts complete the paper and show the potential
industrial applicability of ADRC
Flexible function block implementation of the balance-based adaptive controller as the potential alternative for PID-based industrial applications
Disuccinyl Betulin Triggers Metacaspase-Dependent Endonuclease G-Mediated Cell Death in Unicellular Protozoan Parasite Leishmania donovani
The unicellular organism Leishmania undergoes apoptosis-like cell death in response to external stress or exposure to antileishmanial agents. Here, we showed that 3-O,28-O-disuccinyl betulin (DiSB), a potent topoisomerase type IB
inhibitor, induced parasitic cell death by generating oxidative stress. The characteristic feature of the death process resembled the programmed cell death (PCD) seen in higher eukaryotes. In the current study, the generation of reactive oxygen species (ROS), followed by the depolarization of mitochondrial membrane potential (��m), caused a loss in ATP production in Leishmania
parasites. This further gave positive feedback to produce a large amount of ROS, which in turn caused oxidative DNA
lesions and genomic DNA fragmentation. The treatment of promastigotes with DiSB induced high expression levels of metacaspase protein that led to cell death in this unicellular organism. The PCD was insensitive to benzyloxycarbonyl-Val-Ala-Asp( OMe)-fluoromethylketone (zVAD-fmk), suggesting that the death process was not associated with the activation of caspases.
DiSB treatment translocated Leishmania donovani endonuclease G (LdEndoG) from mitochondria to the nucleus, which was responsible for the DNA degradation process. Conditional antisense knockdown of L. donovani metacaspase (LdMC), as well as EndoG, -subverted death of the parasite and rescued cell cycle arrest in G1 phase. The present study on the effector molecules associated with the PCD pathway of the parasite should help to manifest the mechanisms of PCD and also might be exploited in
antileishmanial chemotherapy