Spinal cord from body donors is suitable for multicolor immunofluorescence

Immunohistochemistry is a powerful tool for studying neuronal tissue from humans at the molecular level. Obtaining fresh neuronal tissue from human organ donors is difficult and sometimes impossible. In anatomical body donations, neuronal tissue is dedicated to research purposes and because of its easier availability, it may be an alternative source for research. In this study, we harvested spinal cord from a single organ donor 2 h (h) postmortem and spinal cord from body donors 24, 48, and 72 h postmortem and tested how long after death, valid multi-color immunofluorescence or horseradish peroxidase (HRP) immunohistochemistry is possible. We used general and specific neuronal markers and glial markers for immunolabeling experiments. Here we showed that it is possible to visualize molecularly different neuronal elements with high precision in the body donor spinal cord 24 h postmortem and the quality of the image data was comparable to those from the fresh organ donor spinal cord. High-contrast multicolor images of the 24-h spinal cords allowed accurate automated quantification of different neuronal elements in the same sample. Although there was antibody-specific signal reduction over postmortem intervals, the signal quality for most antibodies was acceptable at 48 h but no longer at 72 h postmortem. In conclusion, our study has defined a postmortem time window of more than 24 h during which valid immunohistochemical information can be obtained from the body donor spinal cord. Due to the easier availability, neuronal tissue from body donors is an alternative source for basic and clinical research

Quantification of damage processes at surfaces and interfaces of building structures using optical methods and active thermography

In this presentation, the specifications, advantages and limits of both methods will be presented. With the light section method, a very precise determination of position is possible. Arbitrary surfaces can be surveyed with an accuracy of about 0.1 mm. 2D photos can be concatenated. The disadvantages are the complexity of the experimental set-up as well as the data analysis. Latter will be further developed in the presented work. With active thermography, inhomogeneities below the surface can be detected up to a depth of about 10 cm. A maximum spatial resolution of 0.3 mm is possible, but can be enhanced by using a close-up lens. For recording of congruent mappings of the object under investigation, first the internal aberrations of the IR cameras have been corrected (internal camera calibration) by using a freeware matlab toolbox. This calibration reveals, that uncorrected thermograms show considerable distortions up to 5 % at the boundaries, which cannot be neglected for datafusion. For facilitating the fusion to the 3D data, parallel to the capturing of thermograms digital photos are taken from the measurement object. For this, IR camera and digital camera were both mounted into a common frame structure enabling a reproducible relative position. Both methods have been applied to several historic buildings, compiling experimental data that will be presented in the following. Investigations of a sculpture (Madonna with child in the dome of Halberstadt) and of a sandstone column (dome of Magdeburg) are presented. With the help of the introduced approach and the developed software the thermograms can be visualized and analyzed three-dimensional for any complex object geometry. The combination of infrared images of unsteady thermal heat transfer processes with geometric 3D data enables the discrimination between external geometrical effects due to material properties and internal faults. Temporal changes can be observed with the demanded high local accuracy and damage can be recognized on time

Investigating historic masonry structures at different depths with active thermography

Abstract As shown recently, the quantification of damages in historic masonry structures is possible by using active thermography. In this paper, a case study is presented concerning systematic studies of the determination of damage depth and size by using different approaches of active thermography. Various heating sources as well as impulse and periodic heating will be compared. A combination with geometrical 3D data recorded with a laser scanning system (light section methods) demonstrates the complementarities of both methods. Reproducible investigations in regular time intervals for structural monitoring are possible

Investigating historic masonry structures with a combination of active thermography and 3D laser scanner

Methods for the combination (i. e. comparison and overlay) and data fusion (i. e. integration of all data in one data set, replacement of data) of active thermography and 3D laser scanner (light section method) have been developed. Systematic investigations for quantification of damage in historic structures are presented using both techniques. A case study shows that reproducible investigations at regular time intervals are very well suited for structural monitoring

Monitoring of cracks in historic concrete structures using optical, thermal and acoustical methods

Cracks are a major issue in the field of cultural heritage. In order to evaluate the significance of a crack, a long term monitoring of the damaged region is required. However, there is a lack of easy to operate tools for such monitoring measures. Therefore, new or existing methods for other applications have to be optimised for cultural heritage investigation. The paper describes the application of such crack observation methods on a historic concrete sculpture. Beside conventional methods, like mapping by hand and ultrasonic depth profiling, a novel tracking system is presented. Furthermore, the suitability of active thermography for the investigation of cracks was investigated. The results show promising prospects for these non-destructive techniques

Proof of concept for multiple nerve transfers to a single target muscle

Surgical nerve transfers are used to efficiently treat peripheral nerve injuries, neuromas, phantom limb pain, or improve bionic prosthetic control. Commonly, one donor nerve is transferred to one target muscle. However, the transfer of multiple nerves onto a single target muscle may increase the number of muscle signals for myoelectric prosthetic control and facilitate the treatment of multiple neuromas. Currently, no experimental models are available. This study describes a novel experimental model to investigate the neurophysiological effects of peripheral double nerve transfers to a common target muscle. In 62 male Sprague-Dawley rats, the ulnar nerve of the antebrachium alone (n=30) or together with the anterior interosseus nerve (n=32) was transferred to reinnervate the long head of the biceps brachii. Before neurotization, the motor branch to the biceps’ long head was transected at the motor entry point. Twelve weeks after surgery, muscle response to neurotomy, behavioral testing, retrograde labeling, and structural analyses were performed to assess reinnervation. These analyses indicated that all nerves successfully reinnervated the target muscle. No aberrant reinnervation was observed by the originally innervating nerve. Our observations suggest a minimal burden for the animal with no signs of functional deficit in daily activities or auto-mutilation in both procedures. Furthermore, standard neurophysiological analyses for nerve and muscle regeneration were applicable. This newly developed nerve transfer model allows for the reliable and standardized investigation of neural and functional changes following the transfer of multiple donor nerves to one target muscle