Optogenetic stimulation allows activation of cells with high spatial and temporal precision. Here we show direct optogenetic stimulation of skeletal muscle from transgenic mice expressing the light-sensitive channel Channelrhodopsin-2 (ChR2). Largest tetanic contractions are observed with 5-ms light pulses at 30 Hz, resulting in 84% of the maximal force induced by electrical stimulation. We demonstrate the utility of this approach by selectively stimulating with a light guide individual intralaryngeal muscles in explanted larynges from ChR2-transgenic mice, which enables selective opening and closing of the vocal cords. Furthermore, systemic injection of adeno-associated virus into wild-type mice provides sufficient ChR2 expression for optogenetic opening of the vocal cords. Thus, direct optogenetic stimulation of skeletal muscle generates large force and provides the distinct advantage of localized and cell-type-specific activation. This technology could be useful for therapeutic purposes, such as restoring the mobility of the vocal cords in patients suffering from laryngeal paralysis.

Background: This analysis aims at evaluating the impact of multidisciplinary tumor boards on clinical outcome of multiple tumor entities, the effect of the specific number of multidisciplinary tumor boards and potential differences between the tumor entities. Methods: By a matched-pair analysis we compared the response to treatment, overall survival, relapse or disease free survival and progression free survival of patients whose cases were discussed in a tumor board meeting with patients whose cases were not. It was performed with patients registered in the cancer registry of the University of Bonn and diagnosed between 2010 and 2016. After the matching process with a pool of 7262 patients a total of 454 patients with 66 different tumor types were included in this study. Results: First, patients with three or more multidisciplinary tumor board meetings in their history show a significantly better overall survival than patients with no tumor board meeting. Second, response to treatment, relapse free survival and time to progression were not found to be significantly different. Third, there was no significant difference for a specific tumor entity. Conclusion: This study revealed a positive impact of a higher number of multidisciplinary tumor boards on the clinical outcome. Also, our analysis hints towards a positive effect of multidisciplinary tumor boards on overall survival.

Objective: Epistaxis in children is one of the most common causes for seeking professional medical help. Patients may be treated by several disciplines with various approaches to pediatric epistaxis. We reviewed cases of pediatric epistaxis from an otorhinolaryngologist's point of view. Methods: A retrospective chart review was performed on all patients younger than 18 years presenting with epistaxis to the Department of Otorhinolaryngology at the University of Bonn, Germany. Results: Sixty episodes of epistaxis in 58 patients were included in the study. Mean age was 10.1 ± 4.5 years. In terms of risk factors, 3 patients had a hemorrhagic diathesis, 3 had taken medication that interfered with hemostasis, and 8 had a history of previous trauma, most of which was digital manipulation. Twenty-six patients did not need invasive therapy. Twenty-six patients received cauterization to control the bleeding, and 4 patients needed surgery. The necessity for surgery was mainly noncooperation. Conclusions: Epistaxis in children is seldom serious. However, hemorrhagic diathesis needs to be kept in mind as a potential cause of epistaxis. In most cases, careful instruction of the patients and the relatives concerning nasal mucosal care is sufficient. If cauterization is necessary, silver nitrate coagulation should be preferred over electrocoagulation.