Depression in Patients with Mastocytosis: Prevalence, Features and Effects of Masitinib Therapy

Depression in patients with mastocytosis is often reported but its prevalence and characteristics are not precisely described. In addition, the impact of therapies targeting mast cells proliferation, differentiation and degranulation on psychic symptoms of depression have never been investigated. Our objective was to determine the prevalence and to describe features of depression in a large cohort of mastocytosis patients (n = 288) and to investigate the therapeutic impact of the protein kinase inhibitor masitinib in depression symptoms. The description of depression was based on the analysis of a database with Hamilton scores using Principal Component Analysis (PCA). Efficacy of masitinib therapy was evaluated using non parametric Wilcoxon test for paired data within a three months period (n = 35). Our results show that patients with indolent mastocytosis present an elevated prevalence of depression (64%). Depression was moderate in 56% but severe in 8% of cases. Core symptoms (such as psychic anxiety, depressed mood, work and interests) characterized depression in mastocytosis patients. Masitinib therapy was associated with significant improvement (67% of the cases) of overall depression, with 75% of recovery cases. Global Quality of Life slightly improved after masitinib therapy and did not predicted depression improvement. In conclusion, depression is very frequent in mastocytosis patients and masitinib therapy is associated with the reduction its psychic experiences. We conclude that depression in mastocytosis may originate from processes related to mast cells activation. Masitinib could therefore be a useful treatment for mastocytosis patients with depression and anxiety symptoms

Single-nanoparticle phase transitions visualized by four-dimensional electron microscopy

The advancement of techniques that can probe the behaviour of individual nanoscopic objects is of paramount importance in various disciplines, including photonics and electronics. As it provides images with a spatiotemporal resolution, four-dimensional electron microscopy, in principle, should enable the visualization of single-nanoparticle structural dynamics in real and reciprocal space. Here, we demonstrate the selectivity and sensitivity of the technique by visualizing the spin crossover dynamics of single, isolated metal–organic framework nanocrystals. By introducing a small aperture in the microscope, it was possible to follow the phase transition and the associated structural dynamics within a single particle. Its behaviour was observed to be distinct from that imaged by averaging over ensembles of heterogeneous nanoparticles. The approach reported here has potential applications in other nanosystems and those that undergo (bio)chemical transformations

Picosecond observation of cation-stepwise delayed and cation-triggered photoinduced intramolecular charge transfer in fluorescent cation probes

International audienceTime-resolved transient absorption and gain spectra with subpicosecond laser excitation are reported for donor-donor and acceptor-donor stilbene-crowns (in each compound the electron donor group is the 15-aza-5-crown macrocycle, D1). The effect of the calcium cation on the photoinduced intramolecular charge transfer (ICT) rate constants are measured. When the cation is on the donor side of the molecular system (class 1: D1CS-Crown), the photoinduced ICT process is slowed down and goes through several intermediates characterized by a distancing of the cation, while a solvent molecule enters its coordination sphere. When the cation is on the acceptor side (class 2: D1DS-Crown,D1DB-Crown and D1DCS-Crown), the photoinduced ICT process becomes too fast to be measured, even on the picosecond scale

Spin transition in [Fe(PM-BiA)(2)(NCS)(2)] studied by the electron paramagnetic resonance of the Mn2+ ion

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Spin transition with a very large thermal hysteresis in a molecular crystal: an EPR study of Fe(PM-PEA)(2)(NCS)(2)

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Spin transition with a very large thermal hysteresis in a molecular crystal: an EPR study of Fe(PM-PEA)(2)(NCS)(2)

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Picosecond Transient Absorption as Monitor of the Stepwise Cation-Macrocycle Decoordination in the Excited Singlet State of 4-(N-Monoaza-15-crown-5)-4'-cyanostilbene

Picosecond absorption spectroscopy of 4-(/V-monoaza-15-crown-5)-4'-cyano stilbene, a polar fluoroionophore of the stilbene-crown series, shows the formation of an intramolecular charge-transfer state (TICT state), in less than 1 ps (k > 10’2 s~’)in acetonitrile (CH3CN) and less than 4 ps (k = (2.5 ± 0.7) x 10” s-1) in butyronitrile (BuCN). When this fluoroionophore is fully engaged in a calcium complex, its electronic excitation leads sequentially from the Franck—Condon state (LM)*, to a cation probe pair (L*M) (k = (2.5 ± 0.5) x 10n s_1 in CH3CN and k = (3.3 ± 0.5) x 10" s_l in BuCN) and to a solvent separated cation probe pair (L*/S/M) (k = (1.4 ± 0.5) x 1010 s_1 in CH3CN and k = (4 ± 0.5) x 1010 s_1 in BuCN). The transient absorption spectra of these three intermediates on the decoordination pathway have been obtained. The increasing charge transfer of the three states is controlled by the ligand exchange in the coordination sphere of the calcium cation

Spin transition in [Fe(PM-BiA)(2)(NCS)(2)] studied by the electron paramagnetic resonance of the Mn2+ ion

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