Factors of Cortical Plasticity in Brachial Plexus Injury

Cortical plasticity is the brain’s capability of decoding new information through growth and reorganization over our whole life spam. It is the basis for good outcomes after reinnervation and for rehabilitation of adult and obstetric brachial plexus injury. Knowledge about cortical reorganization is crucial to reconstructive surgeons and physiotherapists that aim to give their patients a reasonable prognosis. This chapter intends to present and summarize the current literature on how to detect and quantify cortical plasticity and how research on factors that influence cortical plasticity, mainly in relation to peripheral nerve and more precise brachial plexus injury progresses. Peculiarities of adult and obstetric brachial plexus injuries and their treatment are given. We present techniques that visualize and quantify cortical plasticity with focus on functional imaging like fMRI and nTMS as well as molecular aspects. Future research is needed to understand mechanisms of how molecular changes on a synaptic level of a neuron influence the macroscopic plasticity, to improve rehabilitative resources, to understand the exact prognostic value of nTMS in brachial plexus injury and to investigate the therapeutic capability of rTMS

Airway management in neonates and infants: European Society of Anaesthesiology and Intensive Care and British Journal of Anaesthesia joint guidelines.

Airway management is required during general anaesthesia and is essential for life-threatening conditions such as cardiopulmonary resuscitation. Evidence from recent trials indicates a high incidence of critical events during airway management, especially in neonates or infants. It is important to define the optimal techniques and strategies for airway management in these groups. In this joint European Society of Anaesthesiology and Intensive Care (ESAIC) and British Journal of Anaesthesia (BJA) guideline on airway management in neonates and infants, we present aggregated and evidence-based recommendations to assist clinicians in providing safe and effective medical care. We identified seven main areas of interest for airway management: i) preoperative assessment and preparation; ii) medications; iii) techniques and algorithms; iv) identification and treatment of difficult airways; v) confirmation of tracheal intubation; vi) tracheal extubation, and vii) human factors. Based on these areas, Population, Intervention, Comparison, Outcomes (PICO) questions were derived that guided a structured literature search. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to formulate the recommendations based on those studies included with consideration of their methodological quality (strong '1' or weak '2' recommendation with high 'A', medium 'B' or low 'C' quality of evidence). In summary, we recommend: 1. Use medical history and physical examination to predict difficult airway management (1С). 2. Ensure adequate level of sedation or general anaesthesia during airway management (1B). 3. Administer neuromuscular blocker before tracheal intubation when spontaneous breathing is not necessary (1С). 4. Use a videolaryngoscope with an age-adapted standard blade as first choice for tracheal intubation (1B). 5. Apply apnoeic oxygenation during tracheal intubation in neonates (1B). 6. Consider a supraglottic airway for rescue oxygenation and ventilation when tracheal intubation fails (1B). 7. Limit the number of tracheal intubation attempts (1C). 8. Use a stylet to reinforce and preshape tracheal tubes when hyperangulated videolaryngoscope blades are used and when the larynx is anatomically anterior (1C). 9. Verify intubation is successful with clinical assessment and end-tidal CO2 waveform (1C). 10. Apply high-flow nasal oxygenation, continuous positive airway pressure or nasal intermittent positive pressure ventilation for postextubation respiratory support, when appropriate (1B)

Characterization and social correlates of fecal testosterone and cortisol excretion in wild male Saguinus mystax

Reproductive success in male primates can be influenced by testosterone (T) and cortisol (C). We examined them in wild Saguinus mystax via fecal hormone analysis. Firstly, we wanted to characterize male hormonal status over the course of the year. Further we tested the influence of the reproductive status of the breeding female, social instability, and intergroup encounter rates on T levels, comparing the results with predictions of the challenge hypothesis (Wingfield et al., 1990). We also tested for interindividual differences in hormonal levels, possibly related to social or breeding status. We collected data during a 12-mo study on 2 groups of moustached tamarins at the Estación Biológica Quebrada Blanco in northeastern Peru. We found fairly similar T and C levels over the course of the year for all males. Yet an elevation of T shortly after the birth of infants, during the phase of ovarian inactivity of the group’s breeding female, was evident. Hormonal levels were not significantly elevated during a phase of social instability, did not correlate with intergroup encounter rates, and did not differ between breeding and nonbreeding males. Our results confirm the challenge hypothesis (Wingfield et al., 1990). The data suggest that reproductive competition inmoustached tamarins is not based on endocrinological, but instead on behavioral mechanisms, possibly combined with sperm competition.Deutsche Forschungsgemeinschaft (HE 1870/10-1,2

Progenitors from the postnatal and adult mammalian retina-neurogenic competence and plasticity

The mammalian retina develops from stem cells that are of neuroectodermal origin and derive from bilateral evaginations of the neuroepithelium, the optic vesicles. In rats, the differentiation of the six neuronal and the one glial cell types is terminated around postnatal day 12. The retina of adult mammals is a non-neurogenic region and the diseased retina is devoid of any spontaneous regeneration, while in poikilothermic vertebrates, cells at the ciliary margin of the eye proliferate throughout the life of the animals and generate new retinal cells that are integrated into functional retinal circuits. This knowledge initialized the search for such pools of stem and progenitor cells in the mammalian ciliary body (CB) from which neural stem cells (NSCs) have been isolated and characterized. These cells are capable to differentiate into glia and neurons, including retina-specific cell types like photoreceptors. In course of the present study, cell culture protocols for NSCs from the neurogenic regions subventricular zone (SVZ) and hippocampus (HC) of the adult CNS were optimized. Furthermore, optimal conditions for differentiation of SVZ and HC cells into the three major cell classes of the CNS, namely neurons, astroglia and oligodendroglia, were established. Artificial constitutive expression of Notch1 in adult SVZ and HC derived stem cells resulted in upregulation of glial differentiation and downregulation of neuronal differentiation, suggesting that adult CNS derived stem cells are subject to plasticity in terms of their fate determination. Therefore, these cells could provide a promising source for cellular replacement strategies in neurodegenerative models. The results of the NSC culture optimization were the basis for analyses of retinal progenitor cells. The presence and neurogenic potential of mammalian progenitors of the postnatal sensory retina were analyzed by immunocytochemistry and RT-PCR. The results demonstrate that postnatal rodent retina derived cells proliferate in vitro and display some characteristics of NSCs, such as the expression of specific progenitor markers or the ability to incorporate BrdU. On the other hand, self-renewal as determined by clonal assays was not observed, indicating that postnatal cells are restricted in their stem cell potential. Furthermore, postnatal retinal cells grown under the optimized differentiation condition only differentiated along two neural lineages, neurons and astroglia. Stem cell capacities have been demonstrated for pigmented cells of the adult mammalian CB. RPE based neuronal regeneration in adult mammals has not been reported so far. This is surprising, since RPE cells are of neuroectodermal origin. A comparative study of adult rodent CB and RPE cells revealed that both cell types share characteristics, which are reminiscent of NSCs. Growth as neurospheres, proliferation and self-renewal capacities were all comparable to NSCs. Furthermore, both cell types expressed a set of specific retinal stem and progenitor cell markers, such as the proneural homeobox transcription factor Pax6 or the bHLH transcription factor neuroD. Differentiation in the optimized media indicated that CB and RPE cells can differentiate along neuronal and glial lineages, but are devoid of oligodendroglial differentiation. Trans- or de-differentiation processes induce changes in phenotypes and expression profiles of CB and RPE cells. Therefore, one further focus of this study was the analysis of adult mammalian RPE cells with respect to de- and trans-differentiation under the optimized conditions. Differentiated RPE cells acquired neuronal and glial phenotypes in vitro, although the RPE is devoid of such phenotypes in vivo. Furthermore, detection of doublecortin, a transient marker for neuronal precursors, identified de-differentiating RPE cells that not only expressed beta III tubulin, but also acquired a neuronal morphology. Similar results were also obtained for human derived RPE cells. The presented results eventually aim at the comprehension of the basic biological mechanisms, which regulate the restrictions that stem or progenitor cells experience during cessation of development in the mammalian retina. An intriguing idea is to provide stimuli that alter the gene expression from a quiescent somatic cell in the adult retina towards a retinal stem cell and activate its developmental program to generate new neurons in a diseased or injured retina