Diagnostic power of the non-ischaemic forearm exercise test in detecting glycogenosis type V.

BACKGROUND AND PURPOSE: This was a retrospective study to assess the diagnostic value of the non-ischaemic forearm exercise test in detecting McArdle's disease. METHODS: The study is a retrospective diagnostic study over 15 years (1999-2013) on a referred sample of patients suffering from exercise intolerance and various muscle complaints, generally with elevated creatine kinase (CK). In all, 1226 patients underwent the non-ischaemic forearm exercise test. Blood lactate, ammonia and CK levels were analyzed. DNA analyses and/or muscle biopsies were assessed to confirm the diagnosis of McArdle's disease. The results of 60 volunteers were used to compare with the results of study subjects. RESULTS: In this cohort, 40 patients were finally diagnosed with McArdle's disease. Absolute values of lactate and ammonia rise were used to discriminate all McArdle patients from healthy patients. A sensitivity and specificity of respectively 100% and 99.7% were calculated. The 24-h CK level showed no significant difference from the CK level at the day of the test and confirms the safety of the test. CONCLUSIONS: This study has formally assessed the diagnostic value of the non-ischaemic forearm exercise test in the detection of McArdle's disease. Very high sensitivity and specificity were observed. Furthermore, the test is easy to set up and to perform, it is non-traumatic and cost effective. It may circumvent a muscle biopsy in McArdle patients presenting the most common mutations. Hence, it is a perfect and safe screening instrument to detect patients with McArdle's disease. Glycogen storage disease type III patients, however, may show similar patterns to McArdle patients.

Stilbazolium-MPS3 Nanocomposites with Large Second-Order Optical Nonlinearity and Permanent Magnetization.

Intercalated layered materials comprising an organic dye and inorganic MPS(3) [where M is either the manganese ion (Mn(2+)) or the cadmium ion (Cd(2+))] phases have been prepared. The intercalation process induces a spontaneous poling, giving rise to an efficiency of 750 times that of urea in second-harmonic generation for the cadmium derivative. In addition, the manganese derivative displays a permanent magnetization below 40 kelvin. Thus, these materials exhibit both a large optical nonlinearity and magnetic ordering.

Saturation of cubic optical nonlinearity in long-chain polyene oligomers.

The scaling of the cubic nonlinearity gamma with chain length in polyenic molecules has received considerable theoretical attention. Earlier experimental investigations have been restricted to oligomers with fewer than 20 double bonds because of problems associated with the synthesis and solubility of conjugated molecules. These synthetic difficulties have been overcome in the present study by the use of modern living polymerization techniques. Solution measurements of gamma as a function of chain length in long-chain (up to 240 double bonds) model polyene oligomers are reported. A saturation of the increase of gamma with chain length is observed, and the onset of this saturation occurs for chain lengths considerably longer than predicted from theory.

Synthesis of a highly thermally stable octupolar polyimide for nonlinear optics.

A new polyimide with covalently incorporated 4,4'-bis-(dialkylaminostyryl)-2,2'-bipyridine chromophores is described which allows the synthesis of the corresponding NLO octupolar metallo-polymer.

Dipolar donor-acceptor-substituted schiff base complexes with large off-diagonal second-order nonlinear optical tensor components.

The synthesis, characterization, and two-dimensional second-order nonlinear optical (NLO) response of a dipolar NiII donor- acceptor Schiff base complex and the related ligand are reported. Electric-field-induced second-harmonic generation and harmonic light (hyper-Rayleigh) scattering techniques, in combination with INDO/SCI-SOS theoretical calculations, were used to investigate the vector part of the hyperpolarizability tensor and the two-dimensional character of the molecular nonlinearity, respectively. Off-diagonal hyperpolarizability tensors can be related to charge-transfer transitions that are polarized perpendicular to the molecular dipolar axis, while parallel transitions account for the diagonal hyperpolarizability tensor. The role of the metal center in enhancing the two-dimensional NLO response of such molecules is twofold since it acts both as the donor and the bridging moiety of the planar donor-(pi-conjugate-bridge)-acceptor system. These dipolar two-dimensional molecules are interesting candidates from the perspective of polarization-independent NLO materials.

Muscle elastic properties during wrist flexion and extension in healthy sedentary subjects and volley-ball players.

The aim of this study was to determine the effects of gender and chronic hyperactivity (training) on musculo-tendinous stiffness and joint flexibility and to examine in vivo whether those stiffness parameters were correlated. Thus, maximal isometric voluntary contraction, series elastic stiffness during wrist flexion and wrist extension, and wrist flexibility were investigated in healthy sedentary subjects and in women volley-ball players. Maximal isometric contraction and flexibility were measured classically with specific ergometers. Moreover, muscle stiffness measurements were performed thanks to the use of quick-release movements of the wrist, which had previously been maintained in isometric contraction, allowing the calculation of a musculo-tendinous stiffness index. Despite significant differences in maximal voluntary contraction between wrist flexors and wrist extensors for each of the groups tested and between men and women, no significant gender, function or training effects were found upon musculo-tendinous stiffness indices. Flexibility assessments in both women groups demonstrated that active to passive ratios for wrist flexion remain unchanged whereas a significant training-induced increase for wrist extension was observed. Moreover, no significant relationship between women active joint flexibility and musculo-tendinous stiffness indices was found (r(2): 0.0004 - 0.0319, p > 0.05) whatever the muscle function tested. Collectively, the present results suggest that neural factors rather than morphological changes (i. e. muscle architecture and fiber composition) may explain predominantly the functional consequences observed in wrist extension associated with volley-ball training. Moreover, both musculo-tendinous stiffness and joint flexibility give different information about wrist functional status.

A hyperpolar, multichromophoric cyclodextrin derivative: synthesis, and linear and nonlinear optical properties.

A chiral, highly polar, multichromophoric supermolecule has been designed by gathering seven push-pull chromophores onto a beta-cyclodextrin assembling unit through covalent flexible linkers. The photophysical and nonlinear optical properties of this mutichromophoric conical bundle were investigated and compared with those of the monomeric chromophore. The strongly absorbing multichromophoric system combines interesting features: it has a high molecular first-order hyperpolarisability and a very large dipolar moment (u = 38 D) which reveal a self-arrangement of the dipolar chromophores within the supermolecule. The confinement of the push-pull chromophores within the nanoscopic bundle affects their optical properties and promotes interactions: the multichromophoric supermolecule is hypochromically and hypsochromically shifted with respect to its monomeric analogue. In addition, the close proximity promotes excitonic coupling, as well as excimer formation phenomena.