[A case of "juvenile" self-healing cutaneous mucinosis in an adult]. / Mucinose cutanée « juvénile ¼ auto-involutive chez l'adulte.

INTRODUCTION: Self-healing juvenile cutaneous mucinosis (SHJCM) is a stereotypical disease in children characterized by the acute onset of subcutaneous papules and nodules on the face, dorsum of the hands and peri-articular regions that disappear spontaneously within a few months or years. A few cases have been reported in adults, but these display more heterogeneous clinical and histopathological features. Herein we report a case with a juvenile clinical presentation in an adult woman. OBSERVATION: A 36-year-old patient with a history of Von Willebrand disease was referred to our dermatology department following the rapid development of subcutaneous nodules on her face, hands and large joints, together with periorbital edema. Three nodules were surgically removed and histology demonstrated mucin deposition in the dermis with dissociation of collagen fibers. Autoimmune disease, neoplasia, infection and dysthyroidism were ruled out. Bilateral carpal tunnel syndrome was confirmed by electromyogram in this patient carrying out manual work. Treatment with hydroxychloroquine proved unfruitful. After 1.5 years of follow-up, her lesions showed partial regression. CONCLUSION: The form of SHJCM described in pediatric populations may occur in rare cases in adults. Should the name of juvenile mucinosis still be used in this event?

Characterization of fiber ultrashort pulse delivery for nonlinear endomicroscopy.

In this work, we present a detailed characterization of a small-core double-clad photonic crystal fiber, dedicated and approved for in vivo nonlinear imaging endomicroscopy. A numerical and experimental study has been performed to characterize the excitation and collection efficiencies through a 5 m-long optical fiber, including the pulse duration and spectral shape. This was first done without any distal optics, and then the performances of the system were studied by using two kinds of GRIN lenses at the fiber output. These results are compared to published data using commercial double clad fibers and GRIN lenses.

Spectral and fluorescence lifetime endoscopic system using a double-clad photonic crystal fiber.

We present a customized small-core double-clad photonic crystal fiber for spectral and fluorescence lifetime measurements of human samples. In this Letter, the new fiber has been characterized on different fluorophores and samples of human brain tumor; a comparison to a bi-fiber homemade system and a commercial fiber probe was made.

Optimization and characterization of nonlinear excitation and collection through a gradient-index lens for high-resolution nonlinear endomicroscopy.

We report a study of gradient index (GRIN) lenses as a miniaturized micro-objective for in vivo imaging in the context of the development of a nonlinear endomicroscope. A numerical study of the parameters influencing the lateral resolution, excitation, and collection efficiency, when GRIN lens is coupled with a double clad fiber (DCF), is exposed. Four commercial DCFs, previously identified from the literature as potential endoscopic fibers, are simulated. Then, an experimental study characterizes two GRIN lenses (one commercial, one homemade) by their dispersion and nonlinear effects, potential intrinsic fluorescence, and use for fluorescence lifetime measurements. Images of neural cells from brain tissues of mice through a GRIN lens are presented.

Optical properties, spectral, and lifetime measurements of central nervous system tumors in humans.

A key challenge of central nervous system tumor surgery is to discriminate between brain regions infiltrated by tumor cells and surrounding healthy tissue. Although monitoring of autofluorescence could potentially be an efficient way to provide reliable information for these regions, we found little information on this subject, and thus we conducted studies of brain tissue optical properties. This particular study focuses on the different optical quantitative responses of human central nervous system tumors and their corresponding controls. Measurements were performed on different fixed human tumoral and healthy brain samples. Four groups of central nervous system tumors (glioblastoma, diffuse glioma, meningioma and metastasis) were discriminated from healthy brain and meninx control tissues. A threshold value was found for the scattering and absorption coefficient between tumoral and healthy groups. Emission Spectra of healthy tissue had a significant higher intensity than tumoral groups. The redox and optical index ratio were thenn calculated and these also showed significant discrimination. Two fluorescent molecules, NADH and porphyrins, showed distinct lifetim values among the different groups of samples. This study defines several optical indexes that can act as combinated indicators to discriminate healthy from tumoral tissues.

Spectral and lifetime domain measurements of rat brain tumors.

During glioblastoma surgery, delineation of the brain tumor margins is difficult because the infiltrated and normal tissues have the same visual appearance. We use a fiber-optical fluorescence probe for spectroscopic and time domain measurements to assist surgeon in differentiating the healthy and the infiltrated tissues. First study was performed on rats that were previously injected with tumorous cells. Measurements of endogenous tissue fluorescence were performed on fresh and fixed rat tumor brain slices. Spectral characteristics, fluorescence redox ratios and fluorescence lifetime measurements were analyzed. The study aimed at defining an optical index that can act as an indicator for discriminating healthy from tumorous tissue.