Chronische Transplantatdysfunktion

Chronic transplant dysfunction is a complex dynamic pathogenic process. Clinically, a decrease in glomerular filtration rate (GFR) becomes apparent leading to chronic renal insufficiency and dialysis or death from cardiovascular events. Chronic transplant dysfunction can develop into a chronic alIograft nephropathy (CAN) as a specific entity with dynamic progression. CAN includes a collection of immunologic and non-immunologic factors, rejection, ischemia time, donor and recipient characteristics and toxicity of calcineurin inhibitors. Despite improvements in immunosuppression, the long-range prognosis of renal allografts has not improved. Whether modern immunosuppressive concepts with reduction or avoidance of calcineurin inhibitors and a therapy based on antimetabolites, such as mycophenolate or mTOR-inhibitors could lead to a prolongation of transplant survival, remains to be seen.     

Extreme Photosensitivität seit der Kindheit

Ohne Zusammenfassung     

Multimodal—was ist das überhaupt?

In chronic pain syndromes multimodal treatment has proved its efficacy. However, multimodal treatment does not mean randomly combining different interventions in a potpourri of methods. Multimodal treatment must closely follow a well-proved conceptual framework. Those concepts may be well illustrated by therapy of back pain. The most elaborate model for understanding the transition from acute to chronic pain is fear avoidance. Based on this model chronic pain status is understood as a learned consequence, which resulted from patients’ anxious avoidance of body movements. In these cases, treatment of a physical pathology is not the main aim of therapy but rather functional restoration. Those multimodal programs meanwhile have demonstrated their effectiveness. However, good results not only depend on recognition of imperative elements in therapy but also on adhering to essential principles (avoidance of negative anticipation, adequate information with assurance techniques, no training of avoidance, recognition of elements of fear therapy).     

Correction of head movement on PET studies: comparison of methods.

Head movement presents a continuing problem in PET studies. Head restraint minimizes movement but is unreliable, resulting in the need to develop alternative strategies. These include frame-by-frame (FBF) realignment or use of motion tracking (MT) during the scan to realign PET acquisition data. Here we present a comparative analysis of these 2 methods of motion correction. METHODS: Eight volunteers were examined at rest using (11)C-raclopride PET with the radioligand administered as a bolus followed by constant infusion to achieve steady state. Binding potential (BP) was estimated using the ratio method during 2 periods of the scan at steady state. Head movement was compensated by using coregistration between frames (FBF) and 3 methods using MT measurements of head position acquired with a commercially available optical tracking system. RESULTS: All methods of realignment improved test-retest reliability and noise characteristics of the raw data, with important consequences for the power to detect small changes in radiotracer binding, and the potential to reduce false-positive and false-negative results. MT methods were superior to FBF realignment using coregistration on some indices. CONCLUSION: Such methods have considerable potential to improve the reliability of PET data with important implications for the numbers of volunteers required to test hypotheses.