Duchenne's muscular dystrophy involves a defective transsulfuration pathway activity

Duchenne muscular dystrophy (DMD) is the most frequent X chromosome-linked disease caused by mutations in the gene encoding for dystrophin, leading to progressive and unstoppable degeneration of skeletal muscle tissues. Despite recent advances in the understanding of the molecular processes involved in the pathogenesis of DMD, there is still no cure. In this study, we aim at investigating the potential involvement of the transsulfuration pathway (TSP), and its by-end product namely hydrogen sulfide (H2S), in primary human myoblasts isolated from DMD donors and skeletal muscles of dystrophic (mdx) mice. In myoblasts of DMD donors, we demonstrate that the expression of key genes regulating the H2S production and TSP activity, including cystathionine γ lyase (CSE), cystathionine beta-synthase (CBS), 3 mercaptopyruvate sulfurtransferase (3-MST), cysteine dioxygenase (CDO), cysteine sulfonic acid decarboxylase (CSAD), glutathione synthase (GS) and γ -glutamylcysteine synthetase (γ-GCS) is reduced. Starting from these findings, using Nuclear Magnetic Resonance (NMR) and quantitative Polymerase Chain Reaction (qPCR) we show that the levels of TSP-related metabolites such as methionine, glycine, glutathione, glutamate and taurine, as well as the expression levels of the aforementioned TSP related genes, are significantly reduced in skeletal muscles of mdx mice compared to healthy controls, at both an early (7 weeks) and overt (17 weeks) stage of the disease. Importantly, the treatment with sodium hydrosulfide (NaHS), a commonly used H2S donor, fully recovers the impaired locomotor activity in both 7 and 17 old mdx mice. This is an effect attributable to the reduced expression of pro-inflammatory markers and restoration of autophagy in skeletal muscle tissues. In conclusion, our study uncovers a defective TSP pathway activity in DMD and highlights the role of H2S-donors for novel and safe adjuvant therapy to treat symptoms of DMD

CZT-Based Harmonic Analysis in Smart Grid Using Low-Cost Electronic Measurement Boards

This paper validates the use of a harmonic analysis algorithm on a microcontroller to perform measurements of non-stationary signals in the context of smart grids. The increasing presence of electronic devices such as inverters of distributed generators (DG), power converters of charging stations for electric vehicles, etc. can drain non-stationary currents during their operation. A classical fast Fourier transform (FFT) algorithm may not have sufficient spectral resolution for the evaluation of harmonics and inter-harmonics. Thus, in this paper, the implementation of a chirp-Z transform (CZT) algorithm is suggested, which has a spectral resolution independent from the observation window. The CZT is implemented on a low-cost commercial microcontroller, and the absolute error is evaluated with respect to the same algorithm implemented in the LabVIEW environment. The results of the tests show that the CZT implementation on a low-cost microcontroller allows for accurate measurement results, demonstrating the feasibility of reliable harmonic analysis measurements even in non-stationary conditions on smart grids

Decay of Rabi oscillations induced by magnetic dipole interactions in diluted paramagnetic solids

Decay of Rabi oscillations of equivalent spins diluted in diamagnetic solid matrix and coupled by magnetic dipole interactions is studied. It is shown that these interactions result in random shifts of spin transient nutation frequencies and thus lead to the decay of the transient signal. Averaging over random spatial distribution of spins within the solid and over their spectral positions within magnetic resonance line, we obtain analytical expressions for the decay of Rabi oscillations. The rate of the decay in the case when the half-width of magnetic resonance line exceeds Rabi frequency is found to depend on the intensity of resonant microwave field and on the spin concentration. The results are compared with the literature data for E1' centers in glassy silica and [AlO4] centers in quartz.Comment: 14 pages, 3 figure

Effect of random-telegraph laser phase on two-photon absorption

© 1995 The American Physical SocietyMeasurements of two-photon absorption spectra have been made for the case where the exciting laser has a random-telegraph phase. The resulting spectral shapes are compared to theoretical predictions and to previous data taken with a phase-diffusing laser field [Elliott et al., Phys. Rev. A 32, 887 (1985)]. A striking dependence of the absorption spectrum on the second-order coherence of the field was observed. Using the theory for the propagation of second-order spatial coherence, we draw an analogy between diffraction and two-photon absorption which we use to interpret the two-photon absorption spectra.G. N. Sinclair, X. Bao, D. S. Elliott, and M. W. Hamilto

SECOND-HARMONIC INVESTIGATION OF LOW-FREQUENCY AUTO-OSCILLATIONS IN YIG : Ga SPHERE

We report experimental observations of low-frequency auto-oscillations obtained with a technique based on the detection of the second-harmonic emitted by the sample. Kittel mode and several magnetostatic modes, drived above second-order Suhl threshold, display interesting dynamical behaviours : bifurcation, f /3 limit cycles and noisy oscillations

Vulvar lymphoedematous pseudotumours mistaken for aggressive angiomyxoma: Report of two cases

Background: We describe 2 cases of vulvar pseudotumour due to lymphatic obstruction with chronic lymphoedema of unknown cause that presented as a solitary mass that mimicked aggressive angiomyxoma. Material and Methods: Both patients presented with a vulvar mass without medical history of trauma, surgery in the anogenital region or skin diseases. One patient was overweight (BMI = 26). Both surgically resected vulvar specimens were represented by a polypoid mass with a soft and a gelatinous cut surface. Results: Histologically, the presence of an abundant oedematous stroma with spindle-shaped cells and numerous thin-walled small-to-medium vessels may be confused with an aggressive angiomyxoma. The diagnostic key was represented by the massive oedema, rather than myxoid stroma, with the presence of dilated, tortuous lymphatic channels (some surrounded by clusters of lymphocytes) in the dermis. Conclusion: The recognition of these lesions is important because they may be the cause of problems in differential diagnosis and therapeutic management. In fact, such lesions can be mistaken from both the clinical and histological perspective as a primitive tumour of the vulva-like aggressive angiomyxoma. However, these lesions are not true neoplasms and are likely due to lymphatic obstruction with lymphoedema. A simple surgical excision with vulvoplasty is curative. © 2010 S. Karger AG, Basel

Approche couplée pour le développement de matériaux optiques résistants aux radiations

National audienceDe très nombreuses applications sont aujourd'hui envisagées pour les matériaux optiques en environnement radiatif. Ce regain d'intérêt pour l'usage de verres ou fibres optiques dans des environnements hostiles s'explique par leurs avantages inhérents en particulier leur immunité électromagnétique. En revanche, il est également bien établi que les radiations entrainent la génération de défauts ponctuels dans verres amorphes. Ces défauts vont, au niveau macroscopique, entrainer une altération des propriétés optiques du matériau, le plus souvent de la silice amorphe pure ou dopée. Ainsi, les fibres optiques vont, sous irradiation, voir leur atténuation linéique augmenter, pouvant passer que quelques dixièmes de dB par kilomètre à plusieurs dB par mètre aux longueurs d'onde des télécommunications. L'amplitude et les cinétiques temporelles liées à ces phénomènes vont être conditionnées par des paramètres intrinsèques au matériau (composition, procédé de fabrication,...) ou extrinsèques (caractéristiques de l'irradiation, profil d'emploi du matériau). Une revue de ces paramètres et des exemples d'implication au niveau l'intégration des fibres et verres dans différents environnements radiatifs (Laser Mégajoule, applications spatiales, nucléaire civil) seront présentés à la conférence