The complex immune interaction between the transplant and host in vivo is only beginning to be untangled. Recent progress in our understanding of stem cell biology, decellularization techniques, biomaterials and transplantation immunobiology offers the prospect of transplanting airways without the need for lifelong immunosuppression. In addition, progress in airway revascularization, reinnervation and ever-increasingly sophisticated bioreactor design is opening up new avenues for the construction of a tissue-engineered larynx. Finally, 3D printing is a novel technique with the potential to render microscopic control over how cells are incorporated and grown onto the tissue-engineered airway.

As the global health burden of chronic disease increases, end-stage organ failure has become a costly and intractable problem. De novo organ creation is one of the long-term goals of the medical community. One of the promising avenues is that of tissue engineering: the use of biomaterials to create cells, structures, or even whole organs. Tissue engineering has emerged from its nascent stage, with several proof-of-principle trials performed across various tissue types. As tissue engineering moves from the realm of case trials to broader clinical study, three major questions have emerged: (1) Can the production of biological scaffolds be scaled up accordingly to meet current and future demands without generating an unfavorable immune response? (2) Are biological scaffolds plus or minus the inclusion of cells replaced by scar tissue or native functional tissue? (3) Can tissue-engineered organs be grown in children and adolescents given the different immune profiles of children? In this review, we highlight current research in the immunological response to tissue-engineered biomaterials, cells, and whole organs and address the answers to these questions.

rTMS is increasingly used for a variety of neuropsychiatric conditions. There are data to support ‘fast’ rTMS (≥10 Hz) having some positive effects on cognitive functioning, but a dearth of research looking at any such effects of ‘slow’ rTMS. This question is important as cognitive dysfunction accompanies many neuropsychiatric conditions and neuromodulation that potentially enhances or hinders such functioning has important clinical consequences. To determine cognitive effects of slow (≤1 Hz) rTMS, a systematic review of randomized control trials assayed cognition in neurological, psychiatric, and healthy volunteer ≤1 Hz rTMS paradigms. Both active (fast rTMS) and placebo comparators were included. 497 Records were initially obtained; 20 met inclusion criteria for evaluation. Four major categories emerged: mood disorders; psychotic disorders; cerebrovascular accidents; and ‘other’ (PTSD, OCD, epilepsy, anxiety, and tinnitus). Cognitive effects were measured across several domains: attention, executive functioning, learning, and psychomotor speed. Variability of study paradigms and reporting precluded meta-analytical analysis. No statistically significant improvement or deterioration was consistently found in any cognitive domain or illness category. These data support the overall safety of rTMS in not adversely affecting cognitive functioning. There are some data indicating that rTMS might have cognitive enhancing potential, but these are too limited at this time to make any firm conclusions, and the literature is marked by considerable heterogeneity in study parameters that hinder interpretation. Greater consensus is required in future studies in cognitive markers, and particularly in reporting of protocols. Future work should evaluate the effects of rTMS on cognitive training.

Nicotinic acid adenine dinucleotide phosphate (NAADP), the most potent Ca 2؉ mobilizing second messenger discovered to date, has been implicated in Ca 2؉ signaling in some lymphomas and T cell clones. In contrast, the role of NAADP in Ca

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Contact repulsion of growing axons is an essential mechanism for spinal nerve patterning. In birds and mammals the embryonic somites generate a linear series of impenetrable barriers, forcing axon growth cones to traverse one half of each somite as they extend towards their body targets. This study shows that protein disulphide isomerase provides a key component of these barriers, mediating contact repulsion at the cell surface in chick half-somites. Repulsion is reduced both in vivo and in vitro by a range of methods that inhibit enzyme activity. The activity is critical in initiating a nitric oxide/S-nitrosylation-dependent signal transduction pathway that regulates the growth cone cytoskeleton. Rat forebrain grey matter extracts contain a similar activity, and the enzyme is expressed at the surface of cultured human astrocytic cells and rat cortical astrocytes. We suggest this system is co-opted in the brain to counteract and regulate aberrant nerve terminal growth.

An ethically problematic clinical case is used to illustrate the potential importance of understanding clinical ethics in an interdisciplinary context. Whilst much has been written on ethics education for multidisciplinary and interdisciplinary teams, we argue that it is important that both healthcare professions and healthcare teams are able to look outside their own disciplinary ethos and sometimes outside their formal teams when considering the ramifications of an ethical issue. A complex (fictional but based on the authors’ pooled experiences) case involving the delivery of a new-born from a mother with HIV is used to illustrate this, because multiple clinical teams will be involved at different times and in parallel with one another.

2016-12-23T18:44:59