Search results for " Oxygen"

Synthesis and antiproliferative mechanism of action of pyrrolo[3′,2′:6,7] cyclohepta[1,2-d]pyrimidin-2-amines as singlet oxygen photosensitizers

2016

A new series of pyrrolo[3′,2′:6,7]cyclohepta[1,2-d]pyrimidin-2-amines, was conveniently prepared using a versatile and high yielding multistep sequence. A good number of derivatives was obtained and the cellular photocytotoxicity was evaluated in vitro against three different human tumor cell lines with EC50 (0.08–4.96 μM) values reaching the nanomolar level. Selected compounds were investigated by laser flash photolysis. The most photocytotoxic derivative, exhibiting a fairly long-lived triplet state (τ ∼ 7 μs) and absorbance in the UV–Vis, was tested in the photo-oxidations of 9,10-anthracenedipropionic acid (ADPA) by singlet oxygen. The photosentizing properties are responsible for the c…

Tumor-derived immuno-modulators induce overlapping pro-tolerogenic gene expression signatures in human dendritic cells.

2016

Immature dendritic cells (iDCs) and tolerogenic DCs are essential for the induction and maintenance of peripheral tolerance. Tumors produce immuno-modulatory factors which imprint a pro-tolerogenic, maturation-resistant state in DCs. Here we asked for common markers of differentially tolerized human monocyte-derived DC populations. For this, PBMC-derived monocytes were differentiated to DCs in the presence of established immuno-modulators as released by tumors (IL-6, IL-10, TGF-β, glucocorticoid [GC], prostaglandin E2 [PGE2]). Most unstimulated pro-tolerogenic DC populations commonly over-expressed some tolerance-associated markers (ILT-4, IL-10, HO-1) as compared with iDCs. These markers m…

Redox modulation of muscle mass and function

2020

Muscle mass and strength are very important for exercise performance. Training-induced musculoskeletal injuries usually require periods of complete immobilization to prevent any muscle contraction of the affected muscle groups. Disuse muscle wasting will likely affect every sport practitioner in his or her lifetime. Even short periods of disuse results in significant declines in muscle size, fiber cross sectional area, and strength. To understand the molecular signaling pathways involved in disuse muscle atrophy is of the utmost importance to develop more effective countermeasures in sport science research. We have divided our review in four different sections. In the first one we discuss t…

European contribution to the study of ROS : A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)

2017

WOS: 000410470000009

Oxidation-Induced Increase In Photoreactivity of Bovine Retinal Lipid Extract

2017

Open access original paper Source : 10th EPR Workshop on Applications of EPR in Biology and Medicine, 2016 in Krakow, POLAND.; International audience; The mammalian retina contains a high level of polyunsaturated fatty acids, including docosahexaenoic acid (22:6) (DHA), which are highly susceptible to oxidation. It has been shown that one of the products of DHA oxidation-carboxyethylpyrrole (CEP), generated in situ, causes modifications of retinal proteins and induces inflammation response in the outer retina. These contributing factors may play a role in the development of age-related macular degeneration (AMD). It is also possible that some of the lipid oxidation products are photoreactiv…

Contribution of Excited Ozone and Oxygen Molecules to the Formation of the Stratospheric Ozone Layer

2019

The absorption of UV, visible and near IR radiation by O3 produces transient, electronically excited O3. The absorption of thermal IR radiation ( = 9.065, 9.596 and 14.267 µm) produces vibrationally excited O3 molecules. Thermal absorption is likely the main factor in the self-decay of O3. Photoexcitation of ground state by IR and red light radiation produces singlet oxygens and . Chemical reactions in the stratosphere produce them as well. When reacting with ozone, singlet oxygen produces O (3P) and . By doing so, they tend to maintain the prevailing ozone concentration and are thereby important for the stability of the ozone layer. During the daytime, O(1D), and reach their maximum concen…

Cellular mechanisms of IL-17-induced blood-brain barrier disruption.

2009

Recently T-helper 17 (Th17) cells were demonstrated to disrupt the blood-brain barrier (BBB) by the action of IL-17A. The aim of the present study was to examine the mechanisms that underlie IL-17A-induced BBB breakdown. Barrier integrity was analyzed in the murine brain endothelial cell line bEnd.3 by measuring the electrical resistance values using electrical call impedance sensing technology. Furthermore, in-cell Western blots, fluorescence imaging, and monocyte adhesion and transendothelial migration assays were performed. Experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6 mice. IL-17A induced NADPH oxidase- or xanthine oxidase-dependent reactive oxygen species (ROS)…

One repetition maximum bench press performance: A new approach for its evaluation in inexperienced males and females: A pilot study

2014

Summary The aim of this study was to evaluate a new method to perform the one repetition maximum (1RM) bench press test, by combining previously validated predictive and practical procedures. Eight young male and 7 females participants, with no previous experience of resistance training, performed a first set of repetitions to fatigue (RTF) with a workload corresponding to 1/3 of their body mass (BM) for a maximum of 25 repetitions. Following a 5-min recovery period, a second set of RTF was performed with a workload corresponding to 1/2 of participants’ BM. The number of repetitions performed in this set was then used to predict the workload to be used for the 1RM bench press test using May…

Indications for ECMO: we need to look at the patient first

2021

New tricyclic systems as photosensitizers towards triple negative breast cancer cells.

2022

AbstractNineteen pyrrolo[1,2-h][1,7]naphthyridinones and pyrido[2,3-c]pyrrolo[1,2-a]azepinones were synthesized as new tricyclic systems in which the pyridine ring is annelated to the 6,7-dihydroindolizin-8(5H)-one and 5,6,7,8-tetrahydro-9H-pyrrole[1,2-a]azepine-9-one moieties to obtain potential photosensitizing agents. They were tested for their photoantiproliferative activity on a triple-negative breast cancer cell line, MDA-MB-231, in the dark and under UVA light (2.0 J/cm2). We demonstrated that their toxicity, only when exposed to light, was primarily due to the generation of reactive oxygen species while their photodegradation products were not responsible for their activity. The mos…