[The development of real-time multispectral imaging for the diagnostics of bladder cancer]. / Entwicklung der Echtzeitmultispektralbildgebung für die Diagnostik des Harnblasenkarzinoms.

The performance of white light (WL) cystoscopy in the diagnostics of bladder cancer can be optimized by the use of modern imaging modalities, such as photodynamic diagnostics (PDD) and narrow band imaging (NBI). Real-time multispectral imaging (rMSI) enables simultaneous imaging of reflectance and fluorescence modalities in multiple spectral bands. We created a multiparametric cystoscopy image by digital overlapping of several modalities, e.g. WL, enhanced vascular contrast (EVC), raw fluorescence mode, protoporphyrin IX and autofluorescence (AF). The technical development and the subsequent clinical implementation of rMSI required a structured preclinical evaluation process, including both ex vivo and in vivo trials before the technology can be applied in patients. This review article presents the phases of testing, validation and the first clinical application of rMSI in urological endoscopy.

Imaging gene delivery in a mouse model of congenital neuronal ceroid lipofuscinosis.

Adeno-associated virus (AAV)-mediated gene replacement for lysosomal disorders have been spurred by the ability of some serotypes to efficiently transduce neurons in the brain and by the ability of lysosomal enzymes to cross-correct among cells. Here, we explored enzyme replacement therapy in a knock-out mouse model of congenital neuronal ceroid lipofuscinosis (NCL), the most severe of the NCLs in humans. The missing protease in this disorder, cathepsin D (CathD) has high levels in the central nervous system. This enzyme has the potential advantage for assessing experimental therapy in that it can be imaged using a near-infrared fluorescence (NIRF) probe activated by CathD. Injections of an AAV2/rh8 vector-encoding mouse CathD (mCathD) into both cerebral ventricles and peritoneum of newborn knock-out mice resulted in a significant increase in lifespan. Successful delivery of active CathD by the AAV2/rh8-mCathD vector was verified by NIRF imaging of mouse embryonic fibroblasts from knock-out mice in culture, as well as by ex vivo NIRF imaging of the brain and liver after gene transfer. These studies support the potential effectiveness and imaging evaluation of enzyme replacement therapy to the brain and other organs in CathD null mice via AAV-mediated gene delivery in neonatal animals.

Diffractive properties of volume phase gratings in photorefractive sillenite crystals of arbitrary cut under the influence of an external electric field.

We study the influence of bias dc electric field on the optical properties of volume phase gratings formed in optically active photorefractive sillenite crystals. By considering a general case where the external electric bias direction, the grating vector orientation, the light propagation direction (crystal cut), and state of polarization are arbitrary, we deduce analytical expressions for the diffraction efficiency and the polarization state of the diffracted beam. The influence of the inverse piezoelectric effect is taken into account both in the uniform and the spatially varying part of the impermeability tensor, as well as into the calculation of the effective static permittivity. A theoretical comparative study of the dynamic behavior of the diffraction efficiency as a function of the physical parameters that affect the diffraction process (crystal cut, electric bias, input polarization, and grating orientation) along with experimental verification is provided. The general analytical solution provides means of exploitation of the capabilities of sillenite crystals in several applications.