Take time to draw breath

Application of the bacterial enzyme, chondroitinase, led to restoration of breathing even after long term paralysis of the diaphragm, it was revealed at a press event at the annual Society for Neuroscience meeting. Philippa Warren, a Case Western Reserve scientists and lead on this work, described how the paralysed diaphragm recovered function after a remarkable 1.5 years post injury. "This treatment holds great promise for those with respiratory dysfunction", said Warren. Case Western's own press release can be read here.

A subsequent poster [#523.10] expanding on her work revealed that some of the animals treated responded perhaps too well to the treatment resulting in a less than rhythmic pattern of muscle contraction. Investigation showed that there was particularly strong reactivation of excitatory nerve fibres and that recovery and function in these was likely to be responsible for the recovery. Indeed, treating with a drug that could interfere with signals from these fibres brought things back in line.

Elsewhere, Kevin Hoy was reporting similar (respiratory) recovery after treatment with a licensed anti-cancer drug[#523.08]. Taxol is used in chemotherapy and stabilises the cellular scaffolding in cells. At low doses, however, the stabilisation appears to make for a more robust growth response in nerve fibres. Taxol is by its nature toxic but the dose used in these studies was 1/100 that used clinically. Nevertheless, Hoy looked at whether a less toxic drug with similar properties also led to recovery of breathing function. Alas, no but further work does need to be done, he said.

I was also impressed with Caitlin Hill's study [#523.26]. We know that cellular grafts often survive poorly and efficacy is disappointing. The question Hill set out to answer was; is the lack of effect due to poor choice of cells or simply due to so much cell death which in and of itself has a negative impact on the outcome? It's a subtle question but potentially an important one to answer given the shear amount of effort going into cell transplantations these days.